wcte12xp: Look for multiple loopup codes before setting looping up the framer.

This brings the wcte12xp driver in line with the wct4xxp driver. It also
eliminates the chance that the local side will errouneously go into loopup when
switched from E1 to T1 mode via the spantype sysfs attribute.

Internal-Issue-ID: DAHDI-1038
Signed-off-by: Shaun Ruffell <sruffell@digium.com>
dahdi: Prevent potential error when only switching spantype of single span.

If you have a multiple span system configured for t1 mode, and you try to change
only the first span from t1 to e1 via sysfs, you could get an error in the
kernel log about trying to create duplicate channel.

The problem is that the check for whether there was enough room for the all the
channels of the switched span was wrong.

Reported-by: James Brown <jbrown@digium.com>
Signed-off-by: Shaun Ruffell <sruffell@digium.com>