[RILMODEM] refactor gprs driver

Signed-off-by: Jarko Poutiainen <Jarko.Poutiainen@oss.tieto.com>
[RILMODEM] refactor gprs-context driver

Signed-off-by: Jarko Poutiainen <Jarko.Poutiainen@oss.tieto.com>
[RILMODEM] code review and checkpatch cleaning

Signed-off-by: Jarko Poutiainen <Jarko.Poutiainen@oss.tieto.com>
[RILMODEM] code review and checkpatch cleaning

Signed-off-by: Jarko Poutiainen <Jarko.Poutiainen@oss.tieto.com>
[RILMODEM] fake also roaming

Signed-off-by: Jarko Poutiainen <Jarko.Poutiainen@oss.tieto.com>
Merge pull request #228 from jpoutiai/master

Refactoring rilmodem gprs implementation