efi_loader: refactor switch to non-secure mode

Refactor the switch from supervisor to hypervisor to a new function called
at the beginning of do_bootefi().

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/arch/arm/cpu/armv8/Makefile b/arch/arm/cpu/armv8/Makefile
index 4c4b13c..a5f5433 100644
--- a/arch/arm/cpu/armv8/Makefile
+++ b/arch/arm/cpu/armv8/Makefile
@@ -14,6 +14,7 @@
 obj-$(CONFIG_ARMV8_SPL_EXCEPTION_VECTORS) += exceptions.o
 else
 obj-y	+= exceptions.o
+obj-y	+= exception_level.o
 endif
 obj-y	+= cache.o
 obj-y	+= tlb.o