boot: Make DISTRO_DEFAULTS select CMDLINE

The implementation of DISTRO_DEFAULTS is done in environment scripts and
requires the command line in order to work. Because of this, select
CMDLINE here.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/boot/Kconfig b/boot/Kconfig
index ba586c8..971c983 100644
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -809,6 +809,7 @@
 
 config DISTRO_DEFAULTS
 	bool "(deprecated) Script-based booting of Linux distributions"
+	select CMDLINE
 	select BOOT_DEFAULTS
 	select AUTO_COMPLETE
 	select CMDLINE_EDITING