MAINTAINERS: Add file patterns for power supply device tree bindings

Submitters of device tree binding documentation may forget to CC
the subsystem maintainer if this is missing.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Sebastian Reichel <sre@kernel.org>

MAINTAINERS

@@ -9066,6 +9066,8 @@ M:	David Woodhouse <dwmw2@infradead.org>
 L:	linux-pm@vger.kernel.org
 T:	git git://git.infradead.org/battery-2.6.git
 S:	Maintained
+F:	Documentation/devicetree/bindings/power/
+F:	Documentation/devicetree/bindings/power_supply/
 F:	include/linux/power_supply.h
 F:	drivers/power/
 X:	drivers/power/avs/