x86: Move efi .S files into the 'lib' directory

These files now need to be in a standard place so that they can be located
by generic Makefile rules. Move them to the 'lib' directory.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/Makefile b/Makefile
index bb108d4..96ddc59 100644
--- a/Makefile
+++ b/Makefile
@@ -1140,7 +1140,7 @@
       cmd_u-boot_payload ?= $(LD) $(LDFLAGS_EFI_PAYLOAD) -o $@ \
       -T u-boot-payload.lds arch/x86/cpu/call32.o \
       lib/efi/efi.o lib/efi/efi_stub.o u-boot.bin.o \
-      $(addprefix arch/$(ARCH)/lib/efi/,$(EFISTUB))
+      $(addprefix arch/$(ARCH)/lib/,$(EFISTUB))
 
 u-boot-payload: u-boot.bin.o u-boot-payload.lds FORCE
 	$(call if_changed,u-boot_payload)