MDCLK_SOURCE_SEL_MASK
intel_de_rmw(display, CDCLK_CTL, MDCLK_SOURCE_SEL_MASK, MDCLK_SOURCE_SEL_CD2XCLK);
#define MDCLK_SOURCE_SEL_CD2XCLK REG_FIELD_PREP(MDCLK_SOURCE_SEL_MASK, 0)
#define MDCLK_SOURCE_SEL_CDCLK_PLL REG_FIELD_PREP(MDCLK_SOURCE_SEL_MASK, 1)