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/chromebook_link64_defconfig b/configs/chromebook_link64_defconfig
index b37292a..b48505a 100644
--- a/configs/chromebook_link64_defconfig
+++ b/configs/chromebook_link64_defconfig
@@ -33,7 +33,7 @@
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_SPL_CPU=y
 CONFIG_SPL_ENV_SUPPORT=y
-CONFIG_SPL_I2C_SUPPORT=y
+CONFIG_SPL_I2C=y
 CONFIG_SPL_DM_SPI_FLASH=y
 CONFIG_SPL_NET_SUPPORT=y
 CONFIG_SPL_PCI=y