usb: typec: tps6598x: Check mode of operation

To prevent loading of the driver when the PD controller is
still in some operational mode that the driver does not
support, checking the mode in driver probe callback
function.

TI PD controllers may be in undefined mode of operation
for example when the application code (firmware) is
completely missing.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>