ril: Remove unneeded check when setting SIM status

ofono_sim_inserted_notify() already checks if there is a SIM state
change, so there is no need to do the same in the driver.
mtk: Remove unneeded check when setting SIM status

ofono_sim_inserted_notify() already checks if there is a SIM state
change, so there is no need to do the same in the driver.
rilmodem: Create SimManager even when no SIM

When there is no SIM, SimManager is still created with Present property
set to zero.
Merge pull request #113 from alfonsosanchezbeato/show-no-sim-present

Show Present property in SimManager even in the no-SIM case