staging: typec: fusb302: Set max supply voltage to 5V

Anything higher then 5V may damage hardware not capable of it, so
the only sane default here is 5V. If a board is able to handle a
higher voltage that should come from board specific data such as
device-tree and not be hard coded into the fusb302 code.

Cc: "Yueyao (Nathan) Zhu" <yueyao@google.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>