drm/amd/display: get dprefclk ss info from integration info table

drm/amd/display: get dprefclk ss info from integration info table

[why & how]
we have two SSC_En:
we get ssc_info from dce_info for MPLL_SSC_EN.
we used to call VBIOS cmdtbl's smu_info's SS persentage for DPRECLK SS info,
is used for DP AUDIO and VBIOS' smu_info table was from systemIntegrationInfoTable.

since dcn35 VBIOS removed smu_info, driver need to use integrationInfotable directly.

Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Charlene Liu <charlene.liu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>