drm/amd/display: prep work for root clock optimization enablement for DCN314

To enable root clock optimizations, we need a number of
register writes and need to account for the difference
in DPSTREAMCLK between DCN31 and DCN314. To prevent
issues, add a number of register writes to
DCCG_MASK_SH_LIST_DCN314_COMMON(), and define dccg314_init()
which is mostly in alignment with dccg31_init() but
accounts for the new DPSTREAMCLK sequence.

Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>