staging: typec: USB Type-C Port Manager (tcpm)

staging: typec: USB Type-C Port Manager (tcpm)

This driver implements the USB Type-C Power Delivery state machine
for both source and sink ports. Alternate mode support is not
fully implemented.

The driver attaches to the USB Type-C class code implemented in
the following patches.

	usb: typec: add driver for Intel Whiskey Cove PMIC USB Type-C PHY
	usb: USB Type-C connector class

This driver only implements the state machine. Lower level drivers are
responsible for
- Reporting VBUS status and activating VBUS
- Setting CC lines and providing CC line status
- Setting line polarity
- Activating and deactivating VCONN
- Setting the current limit
- Activating and deactivating PD message transfers
- Sending and receiving PD messages

The driver provides both a functional API as well as callbacks for
lower level drivers.

Signed-off-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit f0690a25a140b853b1842fa80faf828601bb47e8)