MODSIGN: Simplify Makefile with a Kconfig helper

Signed-off-by: Michal Marek <mmarek@suse.cz>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/init/Kconfig b/init/Kconfig
index be8b7f5..fff4cb1 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1697,6 +1697,15 @@
 
 endchoice
 
+config MODULE_SIG_HASH
+	string
+	depends on MODULE_SIG
+	default "sha1" if MODULE_SIG_SHA1
+	default "sha224" if MODULE_SIG_SHA224
+	default "sha256" if MODULE_SIG_SHA256
+	default "sha384" if MODULE_SIG_SHA384
+	default "sha512" if MODULE_SIG_SHA512
+
 endif # MODULES
 
 config INIT_ALL_POSSIBLE