Kconfig: introduce ARCH_DEFCONFIG to DEFCONFIG_LIST

init/Kconfig contains a list of configs that are searched
for if 'make *config' are used with no .config present.
Extend this list to look at the config identified by
ARCH_DEFCONFIG.

With this change we now try the defconfig targets last.

This fixes a regression reported
by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>

arch/x86/Kconfig

@@ -26,17 +26,10 @@ config X86
 	select HAVE_KVM if ((X86_32 && !X86_VOYAGER && !X86_VISWS && !X86_NUMAQ) || X86_64)
 	select HAVE_ARCH_KGDB if !X86_VOYAGER
 
-config DEFCONFIG_LIST
+config ARCH_DEFCONFIG
 	string
-	depends on X86_32
-	option defconfig_list
-	default "arch/x86/configs/i386_defconfig"
-
-config DEFCONFIG_LIST
-	string
-	depends on X86_64
-	option defconfig_list
-	default "arch/x86/configs/x86_64_defconfig"
+	default "arch/x86/configs/i386_defconfig" if X86_32
+	default "arch/x86/configs/x86_64_defconfig" if X86_64
 
 
 config GENERIC_LOCKBREAK

init/Kconfig

@@ -13,6 +13,7 @@ config DEFCONFIG_LIST
 	default "/lib/modules/$UNAME_RELEASE/.config"
 	default "/etc/kernel-config"
 	default "/boot/config-$UNAME_RELEASE"
+	default "$ARCH_DEFCONFIG"
 	default "arch/$ARCH/defconfig"
 
 menu "General setup"