m7vzw: remove SplitSMS and enable MultiPartSMS

Verizon supports multipartSMS so enable it and remove sms spliting
every 160 chars.

Change-Id: Icea9ef9d0a51c3555d34295b274897b496825753
m7vzw: remove duplicate

Change-Id: I81364ee559154798ad2a3f36c4ce197ed130d75e