drm/amd/display: Set MPC_SPLIT_DYNAMIC for DCN10

Since DC version 3.2.226, DC started to use a new internal commit
sequence that better deals with multiple hardware constraints. One of
the improvements is a more reliable sequence for pipe split. Due to the
transition made in version 3.2.226, it should be more reliable to use
the pipe policy as MPC_SPLIT_DYNAMIC, and this commit makes this change.

Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>