SNPS_PHY_MPLLB_SSCEN
intel_de_write(display, SNPS_PHY_MPLLB_SSCEN(phy), pll_state->mpllb_sscen);
pll_state->mpllb_sscen = intel_de_read(display, SNPS_PHY_MPLLB_SSCEN(phy));