cm: add selective based spn (2/2)

* patch set 1 to 7 doesn't fix the problem, it bruce forces the spn
list to ALL DEVICES.
* this change and http://review.cyanogenmod.org/#/c/57393/
will attack the problem at lowest level, customized it for speed
and memory.
*  the best part is that it handles letters and exit the
function when it find a letter in the response from ril.

Change-Id: Ia63309acf38617e68b98ff1068463a942fa793df