make_netboot: Enable I2C device driver for netboot kernel

This is needed as I2C device driver is also built-in for install shim
kernel.

BUG=chrome-os-partner:16712
TEST=Build netboot image and check I2C device driver is included.

Change-Id: I71f21eea9cf599454fe18bd8adeeaa629d851db6
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/41076
Reviewed-by: Bernie Thompson <bhthompson@chromium.org>
1 file changed