arm: imx6: tqma6: implement IMX_CONFIG with Kconfig

Now that we have the Kconfig based CPU type selection,
use this to fill the IMX_CONFIG automatically

Signed-off-by: Markus Niebel <Markus.Niebel@tq-group.com>
diff --git a/board/tqc/tqma6/Kconfig b/board/tqc/tqma6/Kconfig
index 3e4d9f5..ce47ba4 100644
--- a/board/tqc/tqma6/Kconfig
+++ b/board/tqc/tqma6/Kconfig
@@ -33,4 +33,8 @@
 
 endchoice
 
+config IMX_CONFIG
+	default "board/tqc/tqma6/tqma6q.cfg" if TQMA6Q
+	default "board/tqc/tqma6/tqma6s.cfg" if TQMA6S
+
 endif