efi: Drop the efi_ prefix on the arch-specific stub files

These are already in the lib/efi/ directory so the extra efi_ prefix is
redundant and makes files harder to find. Drop it.

Signed-off-by: Simon Glass <sjg@chromium.org>

Makefile

@@ -1696,7 +1696,7 @@ EFI_STUB_ARCH := $(if $(CONFIG_ARM64),arm64,$(if $(CONFIG_X86_64),x86,$(ARCH)))
 quiet_cmd_u-boot_payload ?= LD      $@
       cmd_u-boot_payload ?= $(LD) $(LDFLAGS_EFI_PAYLOAD) -o $@ \
       -T u-boot-payload.lds $(if $(CONFIG_X86),arch/x86/cpu/call32.o,) \
-      lib/efi_client/efi.o lib/efi_client/efi_stub_$(EFI_STUB_ARCH).o \
+      lib/efi_client/efi.o lib/efi_client/stub_$(EFI_STUB_ARCH).o \
       u-boot.bin.o $(addprefix arch/$(ARCH)/lib/,$(EFISTUB))
 
 quiet_cmd_u-boot_payload_arm64.efi ?= OBJCOPY $@

lib/efi_client/Makefile

@@ -7,9 +7,9 @@ obj-$(CONFIG_EFI_APP) += sdram.o
 obj-$(CONFIG_EFI_STUB) += efi_info.o
 
 ifeq ($(CONFIG_ARM64),y)
-stub_obj := efi_stub_arm64.o
+stub_obj := stub_arm64.o
 else
-stub_obj := efi_stub_x86.o
+stub_obj := stub_x86.o
 
 ifeq ($(CONFIG_EFI_STUB_64BIT),y) # && !CONFIG_ARM64
 CFLAGS_REMOVE_$(stub_obj) := -march=i386 -m32