gpio: introduce GPIO_DAVINCI kconfig option

The compatible to Davinci GPIO HW block is used by other TI SoCs, like
Keystone, where GPIO support is declared as optional.

Hence, introduce GPIO_DAVINCI Kconfig option which will allow to enable
Davinci GPIO driver for Keystone SoCs when needed. At same time, kept
Davinci GPIO driver enabled for Davinci SoCs by default.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 0f04444..7c75f5a 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -115,6 +115,13 @@
 	help
 	  Say yes here to support GPIO on CLPS711X SoCs.
 
+config GPIO_DAVINCI
+	bool "TI Davinci/Keystone GPIO support"
+	default y if ARCH_DAVINCI
+	depends on ARM && (ARCH_DAVINCI || ARCH_KEYSTONE)
+	help
+	  Say yes here to enable GPIO support for TI Davinci/Keystone SoCs.
+
 config GPIO_GENERIC_PLATFORM
 	tristate "Generic memory-mapped GPIO controller support (MMIO platform device)"
 	select GPIO_GENERIC