Kconfig whitespace fixes

trivial whitespace fixes.  Mostly changing leading spaces to tabs.

Change-Id: I0bdfe2059b90725e64adfc0bdde785b4e406969d
Signed-off-by: Martin Roth <gaumless@gmail.com>
Reviewed-on: http://review.coreboot.org/10000
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/mainboard/aopen/Kconfig b/src/mainboard/aopen/Kconfig
index 7ea4e54..2208e62 100644
--- a/src/mainboard/aopen/Kconfig
+++ b/src/mainboard/aopen/Kconfig
@@ -1,7 +1,7 @@
 if VENDOR_AOPEN
 
 choice
-        prompt "Mainboard model"
+	prompt "Mainboard model"
 
 source "src/mainboard/aopen/*/Kconfig.name"