MAINTAINERS: add drivers/pinctrl/qcom to ARM/QUALCOMM SUPPORT

When running checkpatch.pl on a new pinctrl driver in
drivers/pinctrl/qcom, I noticed a warning about creating
a new maintainer.  The drivers/pinctrl/qcom folder doesn't have
anyone assigned in the MAINTAINERS file.

Let's assign it to ARM/QUALCOMM SUPPORT.
Signed-off-by: Michael Scott <michael.scott@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>

MAINTAINERS

@@ -1600,6 +1600,7 @@ F:	arch/arm/mach-qcom/
 F:	arch/arm64/boot/dts/qcom/*
 F:	drivers/i2c/busses/i2c-qup.c
 F:	drivers/clk/qcom/
+F:	drivers/pinctrl/qcom/
 F:	drivers/soc/qcom/
 F:	drivers/spi/spi-qup.c
 F:	drivers/tty/serial/msm_serial.h