MAINTAINERS: Add entry for rp2 (Rocketport Express/Infinity) driver

I wrote this driver and use it daily on several machines for work, so
why not.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Acked-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS

@@ -7813,6 +7813,12 @@ S:	Maintained
 F:	Documentation/serial/rocket.txt
 F:	drivers/tty/rocket*
 
+ROCKETPORT EXPRESS/INFINITY DRIVER
+M:	Kevin Cernekee <cernekee@gmail.com>
+L:	linux-serial@vger.kernel.org
+S:	Odd Fixes
+F:	drivers/tty/serial/rp2.*
+
 ROSE NETWORK LAYER
 M:	Ralf Baechle <ralf@linux-mips.org>
 L:	linux-hams@vger.kernel.org