platform/chrome: Use proper protocol transfer function

platform/chrome: Use proper protocol transfer function

pkt_xfer should be used for protocol v3, and cmd_xfer otherwise. We had
one instance of these functions correct, but not the second, fall-back
case. We use the fall-back only when the first command returns an
IN_PROGRESS status, which is only used on some EC firmwares where we
don't want to constantly poll the bus, but instead back off and
sleep/retry for a little while.

Fixes: 2c7589af3c4d ("mfd: cros_ec: add proto v3 skeleton")
Signed-off-by: Shawn Nematbakhsh <[email protected]>
Signed-off-by: Brian Norris <[email protected]>
Reviewed-by: Javier Martinez Canillas <[email protected]>
Signed-off-by: Benson Leung <[email protected]>