x86: i2c: Add a stub driver for Intel I2C/SMbus

This is used on most Intel platforms. We don't have a driver for it yet, but
add a stub to handle the init. For now this targets ivybridge so we may want
to add a device tree binding and generalise it when other platforms are
supported.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index bbbc0dc..c75c579 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -21,6 +21,7 @@
 obj-$(CONFIG_SYS_I2C_FSL) += fsl_i2c.o
 obj-$(CONFIG_SYS_I2C_FTI2C010) += fti2c010.o
 obj-$(CONFIG_SYS_I2C_IHS) += ihs_i2c.o
+obj-$(CONFIG_SYS_I2C_INTEL) += intel_i2c.o
 obj-$(CONFIG_SYS_I2C_KONA) += kona_i2c.o
 obj-$(CONFIG_SYS_I2C_LPC32XX) += lpc32xx_i2c.o
 obj-$(CONFIG_SYS_I2C_MVTWSI) += mvtwsi.o