gpio/xilinx: enable for MIPS

MIPSfpga uses the axi gpio controller. Enable the driver for MIPS.
Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -506,7 +506,7 @@ config GPIO_XGENE_SB
 
 config GPIO_XILINX
 	tristate "Xilinx GPIO support"
-	depends on OF_GPIO && (PPC || MICROBLAZE || ARCH_ZYNQ || X86)
+	depends on OF_GPIO && (PPC || MICROBLAZE || ARCH_ZYNQ || X86 || MIPS)
 	help
 	  Say yes here to support the Xilinx FPGA GPIO device