chell: Disable CONFIG_CMD_I2C_XFER to free up flash space
chell: Disable CONFIG_CMD_I2C_XFER to free up flash space

Disable i2c_xfer command to free up some flash space

BRANCH=none
BUG=b:63969337
TEST=make buildall -j.

Change-Id: Ide1a752cf58f9a7180bdfb92eccff17aa36ceaf4
Signed-off-by: Jenny TC <69498ef46fb20cbbe7d8a1d7bc07f9711dcaf0b6@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/806435
Commit-Ready: Jenny Tc <69498ef46fb20cbbe7d8a1d7bc07f9711dcaf0b6@intel.com>
Tested-by: Jenny Tc <69498ef46fb20cbbe7d8a1d7bc07f9711dcaf0b6@intel.com>
Reviewed-by: Shawn N <5259333ce42e3ace6a73988cec7115ed9d3a661a@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec