CDMA RIL: add SVDO support (1/2)

based on Richard Ross's commit

Change-Id: I313edd3c52d1d0b397ca519757470b87882424d7
Enable SVDO (2/2)

https://github.com/CyanogenMod/android_frameworks_base/commit/e233533501f6b80d1e4015a30ec0eedc5f616da4