MAINTAINERS: Add Frank Rowand as DT maintainer

Frank has agreed to step up and help with DT core code maintainership.
At the same time, Grant is taking a step back from active maintainership
responsibilities. Add Frank to the device tree core code entry and
shuffle Grant to the end of the list. In a few releases time Grant will
be removed entirely.
Signed-off-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NRob Herring <robh@kernel.org>

MAINTAINERS

@@ -7521,8 +7521,9 @@ F:	Documentation/i2c/busses/i2c-ocores
 F:	drivers/i2c/busses/i2c-ocores.c
 
 OPEN FIRMWARE AND FLATTENED DEVICE TREE
-M:	Grant Likely <grant.likely@linaro.org>
 M:	Rob Herring <robh+dt@kernel.org>
+M:	Frank Rowand <frowand.list@gmail.com>
+M:	Grant Likely <grant.likely@linaro.org>
 L:	devicetree@vger.kernel.org
 W:	http://www.devicetree.org/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/glikely/linux.git