Expose Type-C OTG port to sysfs

- Add ability to dynamically change between host and peripheral modes
- Since port does not support PDO, do not add ability to select
[source|sink] for power_role

Tested:
- "echo [host|device] > /sys/class/typec/port0/data_role"

Change-Id: I14e6b8b1e893aaae417c3c9c908e368f8e76f962
1 file changed