bip: add i2c mux for bip

We need to control the i2c mux before we can flash the ITE8320 EC on
bip.

BRANCH=none
BUG=b:79533605
TEST=ran dut-control dut_i2c_mux:ec_prog and saw that ftdi try to write
the correct values to bus (but I don't have a bip to try with)

Change-Id: I5af9c7fc781ce6fc0c6c0c6b4f4c03fd217d93f9
Signed-off-by: Jett Rink <jettrink@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1054559
Tested-by: Nick Sanders <nsanders@chromium.org>
Reviewed-by: Nick Sanders <nsanders@chromium.org>
1 file changed