SKL_DPLL_CTRL1
portSel = read32(SKL_DPLL_CTRL1);
write32(SKL_DPLL_CTRL1, portSel | (1 << (*pllSel * 6)));
TRACE("Skylake DPLL_CTRL1: 0x%" B_PRIx32 "\n", read32(SKL_DPLL_CTRL1));
linkBandwidth = (read32(SKL_DPLL_CTRL1) >> (1 + 6 * pllSel)) & SKL_DPLL_DP_LINKRATE_MASK;