drm/amd/display: get socBB from VBIOS for dcn302 and dcn303

drm/amd/display: get socBB from VBIOS for dcn302 and dcn303

[why]
Some SOC BB paramters may vary per SKU, and it does
not make sense for driver to hardcode these values.
This change was added for dcn30 and dcn301, but not
for dcn302 and dcn303

[how]
Parse the values from VBIOS if available, and use
them if valid

Fixes: 93669c8e480dca ("drm/amd/display: get socBB from VBIOS")
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Bindu Ramamurthy <bindu.r@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>