MAINTAINERS: add USB support to GXP

Add the usb driver and dt-binding documents

Signed-off-by: Richard Yu <richard.yu@hpe.com>

MAINTAINERS

@@ -2215,15 +2215,20 @@ F:	arch/arm/mach-sa1100/jornada720.c
 ARM/HPE GXP ARCHITECTURE
 M:	Jean-Marie Verdun <verdun@hpe.com>
 M:	Nick Hawkins <nick.hawkins@hpe.com>
+M:	Richard Yu <richard.yu@hpe.com>
 S:	Maintained
 F:	Documentation/devicetree/bindings/arm/hpe,gxp.yaml
 F:	Documentation/devicetree/bindings/spi/hpe,gxp-spifi.yaml
 F:	Documentation/devicetree/bindings/timer/hpe,gxp-timer.yaml
+F:	Documentation/devicetree/bindings/usb/hpe,gxp-udc.yaml
+F:	Documentation/devicetree/bindings/usb/hpe,gxp-udcg.yaml
+F:	Documentation/devicetree/bindings/usb/hpe,gxp-uvhc.yaml
 F:	arch/arm/boot/dts/hpe-bmc*
 F:	arch/arm/boot/dts/hpe-gxp*
 F:	arch/arm/mach-hpe/
 F:	drivers/clocksource/timer-gxp.c
 F:	drivers/spi/spi-gxp.c
+F:	drivers/usb/gadget/udc/gxp_udc.c
 F:	drivers/watchdog/gxp-wdt.c
 
 ARM/IGEP MACHINE SUPPORT