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_loader/Kconfig b/lib/efi_loader/Kconfig
index 6b245f5..eb2d6fd 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -14,6 +14,7 @@
 	depends on DM_ETH || !NET
 	depends on !EFI_APP
 	default y if !ARM || SYS_CPU = armv7 || SYS_CPU = armv8
+	select CHARSET
 	select DM_EVENT
 	select EVENT_DYNAMIC
 	select LIB_UUID