librmnetctl: Add support to create device name as specified by user

rmnet_data assigns device name by the order they are created.
This causes problems which multiple processes are trying to
create devices and leads to random device names.

Assign device name as specified by user.

CRs-Fixed: 2018794
Change-Id: Ie0630611d658418b067df796321f4c3f565b9661
3 files changed