staging: typec: tcpm: Set correct flags in PD request messages

We do support USB PD communication, and devices supported by this driver
typically use USB power for purposes other than USB communication.

Originally-from: Puma Hsu <puma_hsu@htc.com>
Cc: Yueyao Zhu <yueyao.zhu@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>