armv8: layerscape: Enable falcon boot

Add jump_to_image_linux() for arm64. Add "noreturn" flag to
armv8_switch_to_el2(). Add hooks to fsl-layerscape to enable falcon
boot.

Signed-off-by: York Sun <york.sun@nxp.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Łukasz Majewski <lukma@denx.de>
Tested-by: Łukasz Majewski <lukma@denx.de>
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 79bd19a..1d7d4f3 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -215,8 +215,8 @@
  * @entry_point: kernel entry point
  * @es_flag:     execution state flag, ES_TO_AARCH64 or ES_TO_AARCH32
  */
-void armv8_switch_to_el2(u64 args, u64 mach_nr, u64 fdt_addr,
-			 u64 arg4, u64 entry_point, u64 es_flag);
+void __noreturn armv8_switch_to_el2(u64 args, u64 mach_nr, u64 fdt_addr,
+				    u64 arg4, u64 entry_point, u64 es_flag);
 /*
  * Switch from EL2 to EL1 for ARMv8
  *