drivers/usb/typec/tps6598x.c: fix portinfo width

Portinfo bit field is 3 bits wide, not 2 bits. This led to
a wrong driver configuration for some tps6598x configurations.

Fixes: 0a4c005b

 ("usb: typec: driver for TI TPS6598x USB Power Delivery controllers")
Signed-off-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>