imx8mq: fix FRAC_PLL_REFCLK_SEL_MASK

Coverity reported dead code, however it is FRAC_PLL_REFCLK_SEL_MASK
was wrongly set.

Reported-by: Coverity 10045172
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Ye Li <ye.li@nxp.com>
diff --git a/arch/arm/include/asm/arch-imx8m/clock_imx8mq.h b/arch/arm/include/asm/arch-imx8m/clock_imx8mq.h
index 742cbf3..7109d33 100644
--- a/arch/arm/include/asm/arch-imx8m/clock_imx8mq.h
+++ b/arch/arm/include/asm/arch-imx8m/clock_imx8mq.h
@@ -316,7 +316,7 @@
 #define FRAC_PLL_LOCK_MASK		BIT(31)
 #define FRAC_PLL_CLKE_MASK		BIT(21)
 #define FRAC_PLL_PD_MASK		BIT(19)
-#define FRAC_PLL_REFCLK_SEL_MASK	BIT(16)
+#define FRAC_PLL_REFCLK_SEL_MASK	(0x3 << 16)
 #define FRAC_PLL_LOCK_SEL_MASK		BIT(15)
 #define FRAC_PLL_BYPASS_MASK		BIT(14)
 #define FRAC_PLL_COUNTCLK_SEL_MASK	BIT(13)