armv8/fsl-lsch3: Add fdt-fixup for clock frequency of the DUART nodes

This patch adds the fdt-fixup logic for the clock frequency of the
NS16550A related device tree nodes.

Signed-off-by: Bhupesh Sharma <bhupesh.sharma@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>

arch/arm/cpu/armv8/fsl-lsch3/fdt.c

@@ -60,4 +60,9 @@ void ft_cpu_setup(void *blob, bd_t *bd)
 #ifdef CONFIG_MP
 	ft_fixup_cpu(blob);
 #endif
+
+#ifdef CONFIG_SYS_NS16550
+	do_fixup_by_compat_u32(blob, "ns16550",
+			       "clock-frequency", CONFIG_SYS_NS16550_CLK, 1);
+#endif
 }