Revert "qcom-common: Add RIL startup script for IPv6 tethering"

This reverts commit 239e6250fcf6e4678312dcde4935ffbff35f0be9.
Revert "qcom-common: add common qcom ril class"

This reverts commit 8bbcf1b6c356facc041a25130f1655911de14945.