drm/amd/display: Set min_width and min_height capability for DCN30

Add min_width, min_height fields to dc_plane_cap structure. Set values
to 16x16 for discrete ASICs, and 64x64 for others.

Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Igor Kravchenko <Igor.Kravchenko@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>