efi_loader: imply USB_KEYBOARD_FN_KEYS

UEFI applications like GRUB and SCT assume that function keys are enabled
on the keyboard.

Let EFI_LOADER imply USB_KEYBOARD_FN_KEYS.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index 21ef440..e2cb729 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -15,6 +15,7 @@
 	select HAVE_BLOCK_DEVICE
 	select REGEX
 	imply CFB_CONSOLE_ANSI
+	imply USB_KEYBOARD_FN_KEYS
 	help
 	  Select this option if you want to run UEFI applications (like GNU
 	  GRUB or iPXE) on top of U-Boot. If this option is enabled, U-Boot