arm64: ls1046a: Support semihosting fallback

Use the semihosting_enabled function to determine whether or not to
enable semihosting devices. This allows for graceful fallback in the
event a debugger is not attached.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
diff --git a/arch/arm/cpu/armv8/fsl-layerscape/spl.c b/arch/arm/cpu/armv8/fsl-layerscape/spl.c
index 1a7dde3..5f09ef0 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/spl.c
+++ b/arch/arm/cpu/armv8/fsl-layerscape/spl.c
@@ -12,6 +12,7 @@
 #include <image.h>
 #include <init.h>
 #include <log.h>
+#include <semihosting.h>
 #include <spl.h>
 #include <asm/cache.h>
 #include <asm/global_data.h>
@@ -27,7 +28,7 @@
 
 u32 spl_boot_device(void)
 {
-	if (IS_ENABLED(CONFIG_SPL_SEMIHOSTING))
+	if (semihosting_enabled())
 		return BOOT_DEVICE_SMH;
 #ifdef CONFIG_SPL_MMC
 	return BOOT_DEVICE_MMC1;