gpio/xilinx: Add support for X86 Arch

Core can be accessed via PCIe on X86 platform.
This patch also allows the driver to be used as module.

Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -367,8 +367,8 @@ config GPIO_XGENE
 	  here to enable the GFC GPIO functionality.
 
 config GPIO_XILINX
-	bool "Xilinx GPIO support"
-	depends on PPC_OF || MICROBLAZE || ARCH_ZYNQ
+	tristate "Xilinx GPIO support"
+	depends on OF_GPIO && (PPC_OF || MICROBLAZE || ARCH_ZYNQ || ARCH_X86)
 	help
 	  Say yes here to support the Xilinx FPGA GPIO device
 

drivers/gpio/gpio-xilinx.c

@@ -30,7 +30,7 @@
 #define XGPIO_CHANNEL_OFFSET	0x8
 
 /* Read/Write access to the GPIO registers */
-#ifdef CONFIG_ARCH_ZYNQ
+#if defined(CONFIG_ARCH_ZYNQ) || defined(CONFIG_X86)
 # define xgpio_readreg(offset)		readl(offset)
 # define xgpio_writereg(offset, val)	writel(val, offset)
 #else