drm/radeon: replace 1-element arrays with flexible-array members

Reported by coccinelle, the following patch will move the
following 1 element arrays to flexible arrays.

drivers/gpu/drm/radeon/atombios.h:5523:32-48: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:5545:32-48: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:5461:34-44: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:4447:30-40: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:4236:30-41: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:7095:28-45: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:3896:27-37: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:5443:16-25: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:5454:34-43: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:4603:21-32: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:4628:32-46: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:6285:29-39: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:4296:30-36: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:4756:28-36: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:4064:22-35: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:7327:9-24: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:7332:32-53: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:7362:26-41: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:7369:29-44: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:7349:24-32: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)
drivers/gpu/drm/radeon/atombios.h:7355:27-35: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

)

Signed-off-by: José Pekkarinen <jose.pekkarinen@foxhound.fi>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>