drm/amd/display: Disable DCN401 UCLK P-State support on full updates

[WHY&HOW]
It is not guaranteed even for HW exclusive P-State methods (like
VActive) that P-state will be supported properly until optimize
bandwidth is called, so unconditionally disable it on full updates.

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Signed-off-by: Dillon Varone <dillon.varone@amd.com>
Signed-off-by: Tom Chung <chiahsuan.chung@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>