msm8960: libril: support DATA_NETWORK_STATE_CHANGED_M7/5757

* This UNSOL response behaves the same as the existing
  RESPONSE_DATA_NETWORK_STATE_CHANGED.

Change-Id: I3826d9e968903a761bb4f6691fbb01fef714afc7
ril.cpp: Correct RSRP and RSRQ values reported by Google Play Ed RIL

The GPE RIL reports RSRP and RSRQ as dBm*10, not dBm, when sending the
data for CellInfoLte. Divide the reported values by 10 to conform with
the API.

This should fix fluctuating signal bars (apparent 0 signal strength
with -70 dBm) on jewel and m7spr.

Change-Id: I69f8917f027bf4cf5604c22e3c199c58f42e21d4