Convert CONFIG_SPL_I2C_SUPPORT to Kconfig

Move this option to Kconfig and tidy up existing uses.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/cpu/armv7/am33xx/Kconfig b/arch/arm/cpu/armv7/am33xx/Kconfig
index 54474c2..2d7d1fc 100644
--- a/arch/arm/cpu/armv7/am33xx/Kconfig
+++ b/arch/arm/cpu/armv7/am33xx/Kconfig
@@ -6,6 +6,9 @@
 config SPL_GPIO_SUPPORT
 	default y
 
+config SPL_I2C_SUPPORT
+	default y
+
 config TARGET_AM43XX_EVM
 	bool "Support am43xx_evm"
 	select TI_I2C_BOARD_DETECT
diff --git a/arch/arm/cpu/armv7/omap3/Kconfig b/arch/arm/cpu/armv7/omap3/Kconfig
index e1c981e..65d71cc 100644
--- a/arch/arm/cpu/armv7/omap3/Kconfig
+++ b/arch/arm/cpu/armv7/omap3/Kconfig
@@ -9,6 +9,9 @@
 config SPL_GPIO_SUPPORT
 	default y
 
+config SPL_I2C_SUPPORT
+	default y
+
 choice
 	prompt "OMAP3 board select"
 	optional
diff --git a/arch/arm/cpu/armv7/omap4/Kconfig b/arch/arm/cpu/armv7/omap4/Kconfig
index 48ce9d3..5c8af63 100644
--- a/arch/arm/cpu/armv7/omap4/Kconfig
+++ b/arch/arm/cpu/armv7/omap4/Kconfig
@@ -9,6 +9,9 @@
 config SPL_GPIO_SUPPORT
 	default y
 
+config SPL_I2C_SUPPORT
+	default y
+
 choice
 	prompt "OMAP4 board select"
 	optional
diff --git a/arch/arm/cpu/armv7/omap5/Kconfig b/arch/arm/cpu/armv7/omap5/Kconfig
index 5b049ad..5a15a5c 100644
--- a/arch/arm/cpu/armv7/omap5/Kconfig
+++ b/arch/arm/cpu/armv7/omap5/Kconfig
@@ -9,6 +9,9 @@
 config SPL_GPIO_SUPPORT
 	default y
 
+config SPL_I2C_SUPPORT
+	default y
+
 choice
 	prompt "OMAP5 board select"
 	optional