efi/libstub: EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER should not default to yes

EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER is deprecated, so it should not
be enabled by default.

In light of commit 4da0b2b7 ("efi/libstub: Re-enable command
line initrd loading for x86"), keep the default for X86.

Fixes: cf6b8366 ("efi/libstub: Make initrd file loader configurable")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20201028153402.1736103-1-geert+renesas@glider.beSigned-off-by: Ard Biesheuvel <ardb@kernel.org>

drivers/firmware/efi/Kconfig

@@ -122,7 +122,7 @@ config EFI_ARMSTUB_DTB_LOADER
 config EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER
 	bool "Enable the command line initrd loader" if !X86
 	depends on EFI_STUB && (EFI_GENERIC_STUB || X86)
-	default y
+	default y if X86
 	depends on !RISCV
 	help
 	  Select this config option to add support for the initrd= command