drm/amdgpu: Assign correct bits for SDMA HDP flush

commit aebd3eb9 upstream.

HDP Flush request bit can be kept unique per AID, and doesn't need to be
unique SOC-wide. Assign only bits 10-13 for SDMA v4.4.2.

Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>