console: honor CONFIG_POSTCAR_CONSOLE

The declarations for console_init() were unconditionally
exposed even though there is a Kconfig option. Correct this
by honoring the CONFIG_POSTCAR_CONSOLE condition.

BUG=chrome-os-partner:57513

Change-Id: Id45ae3d7c05a9f4ebcf85c446fc68a709513bb0f
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/16617
Tested-by: build bot (Jenkins)
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/console/Makefile.inc

@@ -18,8 +18,8 @@ romstage-y += init.c console.c
 romstage-y += post.c
 romstage-y += die.c
 
-postcar-y += vtxprintf.c printk.c
-postcar-y += init.c console.c
+postcar-$(CONFIG_POSTCAR_CONSOLE) += vtxprintf.c printk.c
+postcar-$(CONFIG_POSTCAR_CONSOLE) += init.c console.c
 postcar-y += post.c
 postcar-y += die.c