MAINTAINERS: Add a number of "common" directories

A number of platforms have "common" directories that are in turn not
listed by the board MAINTAINERS file.  Add these directories in many
cases.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/toradex/colibri_imx6/MAINTAINERS b/board/toradex/colibri_imx6/MAINTAINERS
index f7a5ad5..25d3a06 100644
--- a/board/toradex/colibri_imx6/MAINTAINERS
+++ b/board/toradex/colibri_imx6/MAINTAINERS
@@ -4,6 +4,7 @@
 W:      https://www.toradex.com/community
 S:	Maintained
 F:	board/toradex/colibri_imx6/
+F:	board/toradex/common/
 F:	include/configs/colibri_imx6.h
 F:	configs/colibri_imx6_defconfig
 F:	arch/arm/dts/imx6dl-colibri-eval-v3.dts