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/P2020RDB-PC_36BIT_NAND_defconfig b/configs/P2020RDB-PC_36BIT_NAND_defconfig
index e0c64f0..85fe2f3 100644
--- a/configs/P2020RDB-PC_36BIT_NAND_defconfig
+++ b/configs/P2020RDB-PC_36BIT_NAND_defconfig
@@ -27,7 +27,7 @@
 CONFIG_SPL_NAND_SUPPORT=y
 CONFIG_TPL=y
 CONFIG_TPL_ENV_SUPPORT=y
-CONFIG_TPL_I2C_SUPPORT=y
+CONFIG_TPL_I2C=y
 CONFIG_TPL_MPC8XXX_INIT_DDR_SUPPORT=y
 CONFIG_TPL_NAND_SUPPORT=y
 CONFIG_TPL_SERIAL_SUPPORT=y