ARM: dts: imx6ull-colibri: change hierarchy of DTS files

Introduce imx6ull-colibri-u-boot.dtsi for u-boot specific properties to
keep original imx6ull-colibri.dts in sync with Linux.

Move all contents of imx6ull-colibri.dts to imx6ull-colibri.dtsi +
additionally fix checkpatch warnings.

Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Igor Opaniuk <igor.opaniuk@toradex.com>
diff --git a/board/toradex/colibri-imx6ull/MAINTAINERS b/board/toradex/colibri-imx6ull/MAINTAINERS
index 626c1f9..c8199fa 100644
--- a/board/toradex/colibri-imx6ull/MAINTAINERS
+++ b/board/toradex/colibri-imx6ull/MAINTAINERS
@@ -4,6 +4,8 @@
 W:	https://www.toradex.com/community
 S:	Maintained
 F:	arch/arm/dts/imx6ull-colibri.dts
+F:	arch/arm/dts/imx6ull-colibri-u-boot.dtsi
+F:	arch/arm/dts/imx6ull-colibri.dtsi
 F:	board/toradex/colibri-imx6ull/
 F:	configs/colibri-imx6ull_defconfig
 F:	include/configs/colibri-imx6ull.h