gpio: Move OMAP_GPIO to Kconfig

This driver is used often enough such that we want to have this enabled
by default on any ARCH_OMAP2PLUS board, and this only compiles on
ARCH_OMAP2PLUS due to required defines, so mark that as the depends.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 325d053..15135e5 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -95,6 +95,14 @@
 	  - APQ8016
 	  - MSM8916
 
+config OMAP_GPIO
+	bool "TI OMAP GPIO driver"
+	depends on ARCH_OMAP2PLUS
+	default y
+	help
+	  Support GPIO controllers on the TI OMAP3/4/5 and related (such as
+	  AM335x/AM43xx/AM57xx/DRA7xx/etc) families of SoCs.
+
 config PM8916_GPIO
 	bool "Qualcomm PM8916 PMIC GPIO/keypad driver"
 	depends on DM_GPIO && PMIC_PM8916