MAINTAINERS: Add co-maintainer for drivers/irqchip

Thomas Gleixner has asked me to assist with the review and merging of
patches for the irqchip subsystem.

Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Link: http://lkml.kernel.org/r/1400006821-32145-1-git-send-email-jason@lakedaemon.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

MAINTAINERS

@@ -4818,6 +4818,14 @@ L:	linux-kernel@vger.kernel.org
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git irq/core
 F:	kernel/irq/
+
+IRQCHIP DRIVERS
+M:	Thomas Gleixner <tglx@linutronix.de>
+M:	Jason Cooper <jason@lakedaemon.net>
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git irq/core
+T:	git git://git.infradead.org/users/jcooper/linux.git irqchip/core
 F:	drivers/irqchip/
 
 IRQ DOMAINS (IRQ NUMBER MAPPING LIBRARY)