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/display5_defconfig b/configs/display5_defconfig
index c81ac41..744dbb5 100644
--- a/configs/display5_defconfig
+++ b/configs/display5_defconfig
@@ -40,7 +40,7 @@
 CONFIG_SPL_DMA=y
 CONFIG_SPL_ENV_SUPPORT=y
 CONFIG_SPL_SAVEENV=y
-CONFIG_SPL_I2C_SUPPORT=y
+CONFIG_SPL_I2C=y
 CONFIG_SPL_OS_BOOT=y
 CONFIG_SPL_SPI_LOAD=y
 CONFIG_SPL_WATCHDOG=y