wwan-config: Increase TimeoutStartSec

As explained in the comment, the start of this service may include some
power cycles of the modem and also the startup of ModemManager. All of
this may take longer than the default 90 seconds in some special cases.

This should anyway not be a problem since this service is self resilient
and can handle errors during startup.

BugzID: 80178

recipes-connectivity/wwan-config/wwan-config/wwan-config@.service

@@ -7,6 +7,8 @@ ExecStart=/usr/bin/wwan-config %I
 PIDFile=/run/%I.pid
 Restart=on-failure
 Nice=-20
+# Start time may include power cycles and start of ModemManager
+TimeoutStartSec=180
 
 [Install]
 RequiredBy=multi-user.target