MAINTAINERS, git-mailrc: update the maintainer for rockchip

Adding myself to MAINTAINERS and git-mailrc for the rockchip
sub-architecture.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index 37cefdb..957e27c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -133,6 +133,7 @@
 
 ARM ROCKCHIP
 M:	Simon Glass <sjg@chromium.org>
+M:	Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
 S:	Maintained
 T:	git git://git.denx.de/u-boot-rockchip.git
 F:	arch/arm/mach-rockchip/