cinterion: change secondary port to ppp on PLS8
Swapping PLS8 ports in 4078d54a was not quite enough, since ACM0 should be used for PPP as in the generic SQPORT probing, not as secondary.
Swapping PLS8 ports in 4078d54a was not quite enough, since ACM0 should be used for PPP as in the generic SQPORT probing, not as secondary.