g2: Read value of network mode from NV
In case of 1xCSFB, when LTE is disabled, modem sends GSM/WCDMA/CDMA
except LTE. And then, device does not recovery LTE mode during 12
minutes. To fix it, this patch reads value of network mode from NV.

Bug: 10788525

Change-Id: I9c7a58bb881c325ba8ff27b2b1fb08d216a9a715