drm/amdgpu/display: add MALL support (v2)

Enable Memory Access at Last Level (MALL) feature for display.

v2: squash in 64 bit division fixes

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>