pinctrl: cygnus: Add new compatible string for gpio controller driver

This new compatible string, "brcm,iproc-gpio", should be used for
all new iproc-based future SoCs.
Signed-off-by: Pramod Kumar <pramodku@broadcom.com>
Reviewed-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Documentation/devicetree/bindings/pinctrl/brcm,cygnus-gpio.txt

@@ -3,8 +3,8 @@ Broadcom Cygnus GPIO/PINCONF Controller
 Required properties:
 
 - compatible:
-    Must be "brcm,cygnus-ccm-gpio", "brcm,cygnus-asiu-gpio", or
-    "brcm,cygnus-crmu-gpio"
+    Must be "brcm,cygnus-ccm-gpio", "brcm,cygnus-asiu-gpio",
+    "brcm,cygnus-crmu-gpio" or "brcm,iproc-gpio"
 
 - reg:
     Define the base and range of the I/O address space that contains the Cygnus