i2c: Rename SPL/TPL_I2C_SUPPORT to I2C

Rename these options so that CONFIG_IS_ENABLED can be used with them.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/configs/Mini-X_defconfig b/configs/Mini-X_defconfig
index 3353d09..89c633c 100644
--- a/configs/Mini-X_defconfig
+++ b/configs/Mini-X_defconfig
@@ -6,7 +6,7 @@
 CONFIG_USB0_VBUS_PIN="PB9"
 CONFIG_VIDEO_COMPOSITE=y
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
-CONFIG_SPL_I2C_SUPPORT=y
+CONFIG_SPL_I2C=y
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_OHCI_HCD=y
 CONFIG_USB_MUSB_HOST=y