drm/amd/display: Include EQU Prefetch Bandwidth For Bandwidth Calculations

[Why]
Pixel data bandwidth required in mode programming (MP) ends up being
higher than what was calculated in mode support (MS) even though
the prefetch bandwidths calculated in MP are lower than the MS ones.

MP used a different equ prefetch schedule than MS which lead a
slight difference in parameters. This resulted in the pixel data
bandwidth in MP to be higher than MS.

[How]
Rename the RequiredPrefetchBWOTO term so it can be applied generically.
Update the value with the EQU bandwidth if the EQU schedule is used.
Get the max prefetch bandwidth that MS calculated and use it
as part of the calculations for required bandwidth.

Reviewed-by: Dillon Varone <dillon.varone@amd.com>
Signed-off-by: Austin Zheng <Austin.Zheng@amd.com>
Signed-off-by: Fangzhi Zuo <jerry.zuo@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>