MSIM: Add support for DSDA.

Add support for below.
1) Maintain LCH & Active subscriptions and inform changes to
lower layers.
2) LCHR and SCH tones
3) Allow calls on other sub, when call is already active
in the current sub.

Change-Id: Id6c774496266afbda61c0ab10610221fab3daa47
10 files changed