drm/amdgpu: do optimization for psp command submit

In the psp command submit logic,
the function msleep(1) delayed too long,
Changing it to usleep_range(10, 100) to
have a better performance.

Signed-off-by: Peng Ju Zhou <PengJu.Zhou@amd.com>
Reviewed-by: Emily.Deng <Emily.Deng@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>