MAINTAINERS: add xtensa irqchips to xtensa port entry

Now that irqchip drivers for xtensa live outside arch/xtensa we'd like
to add them to our maintenance list.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Marc Gauthier <marc@cadence.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS

@@ -8765,6 +8765,7 @@ M:	Max Filippov <jcmvbkbc@gmail.com>
 L:	linux-xtensa@linux-xtensa.org
 S:	Maintained
 F:	arch/xtensa/
+F:	drivers/irqchip/irq-xtensa-*
 
 THANKO'S RAREMONO AM/FM/SW RADIO RECEIVER USB DRIVER
 M:	Hans Verkuil <hverkuil@xs4all.nl>