lib: fix selection of CONFIG_CHARSET

lib/charset.c is not optional for
EFI_APP || EFI_LOADER || UFS || UT_UNICODE.
These must select CONFIG_CHARSET.

Fixes: 726cd9836db0 ("efi: Make unicode printf available to the app")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/lib/efi/Kconfig b/lib/efi/Kconfig
index 15ce99e..c2b9bb7 100644
--- a/lib/efi/Kconfig
+++ b/lib/efi/Kconfig
@@ -14,6 +14,7 @@
 
 config EFI_APP
 	bool "Support running as an EFI application"
+	select CHARSET
 	help
 	  Build U-Boot as an application which can be started from EFI. This
 	  is useful for examining a platform in the early stages of porting