drm/amdgpu/display: include delay.h

For udelay.  This is needed for some platforms.

Reviewed-by: Nicholas Kazlauskas <nicholas.kazluaskas@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Alex Deucher 2019-12-17 15:39:04 -05:00
commit e3250f2d5b