drm/amd/display: enable PCON support for dcn314

[Why]
DCN314 supports PCON.

[How]
Explicitly enable it in dcn314 resources.

Signed-off-by: Roman Li <roman.li@amd.com>
Reviewed-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>