drm/amd/display: update the YUV plane offsets

This patch updates the planes default offsets to
the appropriate ones, and aligns the pitch to 64 bits.

BUG=SWDEV-119421
TEST=Boots to UI on jadeite
TEST=
     plane_test --format AR24 --size 500x50 -p --format YV12 --size 500x500
     plane_test --format AR24 --size 500x50 -p --format YV12 --size 1280x720
     plane_test --format AR24 --size 500x50 -p --format YV12 --size 1366x768

Signed-off-by: Shirish S <shirish.s@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>