XELPDP_DDI_CLOCK_SELECT_DIV18CLK
val |= XELPDP_DDI_CLOCK_SELECT_PREP(display, XELPDP_DDI_CLOCK_SELECT_DIV18CLK);
clock == XELPDP_DDI_CLOCK_SELECT_DIV18CLK)
val |= XELPDP_DDI_CLOCK_SELECT_PREP(display, XELPDP_DDI_CLOCK_SELECT_DIV18CLK);