usb: typec: driver for Intel PMC mux control

The Intel PMC microcontroller on the latest Intel platforms
has a new function that allows configuration of the USB
Multiplexer/DeMultiplexer switches that are under the
control of the PMC.

The Intel PMC mux control (aka. mux-agent) can be used for
swapping the USB data role and for entering alternate modes,
DisplayPort or Thunderbolt3.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20200302135353.56659-10-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>