d3d12: HEVC Encode workaround for edge case in caps reporting not contemplated by...

d3d12: HEVC Encode workaround for edge case in caps reporting not contemplated by upper layer interface

Workaround for https://github.com/intel/libva/issues/641

Example where VAConfigAttribValEncHEVCBlockSizes.max_transform_hierarchy_depth_intra/inter overflows

MinCbLog2SizeY = log2(8) = 3
CtbLog2SizeY = log2(64) = 6
MinTbLog2SizeY = log2(4) = 2
MaxTbLog2SizeY = log2(32) = 5

max_transform_hierarchy_depth_intra = (CtbLog2SizeY − MinTbLog2SizeY) = 4
max_transform_hierarchy_depth_inter = (CtbLog2SizeY − MinTbLog2SizeY) = 4

Reviewed-by: Giancarlo Devich <gdevich@microsoft.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/19119>