usb: typec: tcpm: Keep other events when receiving FRS and Sourcing_vbus events

When receiving FRS and Sourcing_Vbus events from low-level drivers, keep
other events which come a bit earlier so that they will not be ignored
in the event handler.

Fixes: 8dc4bd07 ("usb: typec: tcpm: Add support for Sink Fast Role SWAP(FRS)")
Cc: stable <stable@vger.kernel.org>
Cc: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Badhri Jagan Sridharan <badhri@google.com>
Signed-off-by: Kyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210803091314.3051302-1-kyletso@google.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/typec/tcpm/tcpm.c

@@ -5369,7 +5369,7 @@ EXPORT_SYMBOL_GPL(tcpm_pd_hard_reset);
 void tcpm_sink_frs(struct tcpm_port *port)
 {
 	spin_lock(&port->pd_event_lock);
-	port->pd_events = TCPM_FRS_EVENT;
+	port->pd_events |= TCPM_FRS_EVENT;
 	spin_unlock(&port->pd_event_lock);
 	kthread_queue_work(port->wq, &port->event_work);
 }
@@ -5378,7 +5378,7 @@ EXPORT_SYMBOL_GPL(tcpm_sink_frs);
 void tcpm_sourcing_vbus(struct tcpm_port *port)
 {
 	spin_lock(&port->pd_event_lock);
-	port->pd_events = TCPM_SOURCING_VBUS;
+	port->pd_events |= TCPM_SOURCING_VBUS;
 	spin_unlock(&port->pd_event_lock);
 	kthread_queue_work(port->wq, &port->event_work);
 }