Remove explicit select MMCONF_SUPPORT

Make MMCONF_SUPPORT selected with MMCONF_SUPPORT_DEFAULT.

Platforms that remain to have explicit MMCONF_SUPPORT are
ones that should be converted.

Change-Id: Iba8824f46842607fb1508aa7d057f8cbf1cd6397
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/17527
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/Kconfig

@@ -531,6 +531,7 @@ config MMCONF_SUPPORT_DEFAULT
 
 config MMCONF_SUPPORT
 	bool
+	default y if MMCONF_SUPPORT_DEFAULT
 	default n
 
 source "src/console/Kconfig"