MAINTAINERS: Add patterns for pmic 8921 files to MSM subsystem

Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Acked-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

MAINTAINERS

@@ -931,6 +931,8 @@ F:	drivers/mmc/host/msm_sdcc.h
 F:	drivers/tty/serial/msm_serial.h
 F:	drivers/tty/serial/msm_serial.c
 F:	drivers/platform/msm/
+F:	drivers/*/pm8???-*
+F:	include/linux/mfd/pm8xxx/
 T:	git git://codeaurora.org/quic/kernel/davidb/linux-msm.git
 S:	Maintained