drm/amd/display: Account For OTO Prefetch Bandwidth When Calculating Urgent Bandwidth

[Why]
1) The current calculations for OTO prefetch bandwidth do not consider the number of DPP pipes in use.
As a result, OTO prefetch bandwidth may be larger than the vactive bandwidth if multiple DPP pipes are used.
OTO prefetch bandwidth should never exceed the vactive bandwidth.

2) Mode programming may be mismatched with mode support
In cases where mode support has chosen to use the equalized (equ) prefetch schedule,
mode programming may end up using oto prefetch schedule instead.
The bandwidth required to do the oto schedule may end up being higher than the equ schedule.
This can cause the required urgent bandwidth to exceed the available urgent bandwidth.

[How]
Output the oto prefetch bandwidth and incorperate it into the urgent bandwidth calculations
even if the prefetch schedule being used is not the oto schedule.

Reviewed-by: Dillon Varone <dillon.varone@amd.com>
Signed-off-by: Austin Zheng <Austin.Zheng@amd.com>
Signed-off-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>