efi_loader: rename BOOTEFI_BOOTMGR to EFI_BOOTMGR

At this point, EFI boot manager interfaces is fully independent from
bootefi command. So just rename the configuration parameter.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/efi_loader/Makefile b/lib/efi_loader/Makefile
index f0a31b4..fcb0af7 100644
--- a/lib/efi_loader/Makefile
+++ b/lib/efi_loader/Makefile
@@ -49,7 +49,7 @@
 endif
 
 obj-$(CONFIG_CMD_BOOTEFI_HELLO) += helloworld_efi.o
-obj-$(CONFIG_BOOTEFI_BOOTMGR) += efi_bootmgr.o
+obj-$(CONFIG_EFI_BOOTMGR) += efi_bootmgr.o
 obj-$(CONFIG_EFI_BINARY_EXEC) += efi_bootbin.o
 obj-y += efi_boottime.o
 obj-y += efi_helper.o