MAINTAINERS: Remove myself as qcom maintainer

I no longer regularly work on this platform, and only have a few
increasingly outdated boards.  Andy has primarily been doing the
maintenance.
Signed-off-by: David Brown <david.brown@linaro.org>
Signed-off-by: Andy Gross <agross@kernel.org>

MAINTAINERS

@@ -2044,7 +2044,6 @@ S:	Maintained
 
 ARM/QUALCOMM SUPPORT
 M:	Andy Gross <agross@kernel.org>
-M:	David Brown <david.brown@linaro.org>
 L:	linux-arm-msm@vger.kernel.org
 S:	Maintained
 F:	Documentation/devicetree/bindings/soc/qcom/