mips: mscc: Add generic GPIO control utility function

The GPIO control function can be used for controlling alternate
functions associated with a GPIO.

Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com>
diff --git a/arch/mips/mach-mscc/include/mach/common.h b/arch/mips/mach-mscc/include/mach/common.h
index 92a0555..d18ae78 100644
--- a/arch/mips/mach-mscc/include/mach/common.h
+++ b/arch/mips/mach-mscc/include/mach/common.h
@@ -45,4 +45,6 @@
 		u8 addr,
 		u16 value);
 
+void mscc_gpio_set_alternate(int gpio, int mode);
+
 #endif				/* __ASM_MACH_COMMON_H */