microblaze: Added Kconfig support for CONFIG_XILINX_GPIO

This patch added Kconfig support for CONFIG_XILINX_GPIO
and enabled it in respective defconfig.

Signed-off-by: Vipul Kumar <vipulk@xilinx.com>
Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 34d4409..cc75aec 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -183,6 +183,11 @@
 	  of 'anonymous' GPIOs that do not belong to any device or bank.
 	  Select a suitable value depending on your needs.
 
+config XILINX_GPIO
+	bool "Xilinx GPIO driver"
+	help
+	  This config enable the Xilinx GPIO driver for Microblaze.
+
 config CMD_TCA642X
 	bool "tca642x - Command to access tca642x state"
 	help