armv8/fsl-layerscape: fdt: Skip checking USB clock on LS1012A

USB requires 100MHz clock. On LS1012A, a dedicated 100MHz is provided
instead of SYSCLK (125MHz). Skipping checking SYSCLK for FDT fixup.

Signed-off-by: Yingxi Yu <yingxi.yu@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/arch/arm/cpu/armv8/fsl-layerscape/fdt.c b/arch/arm/cpu/armv8/fsl-layerscape/fdt.c
index 26d4a30..762a95b 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/fdt.c
+++ b/arch/arm/cpu/armv8/fsl-layerscape/fdt.c
@@ -387,8 +387,9 @@
 #ifdef CONFIG_SYS_DPAA_FMAN
 	fdt_fixup_fman_firmware(blob);
 #endif
+#ifndef CONFIG_LS1012A
 	fsl_fdt_disable_usb(blob);
-
+#endif
 #ifdef CONFIG_HAS_FEATURE_GIC64K_ALIGN
 	fdt_fixup_gic(blob);
 #endif