Handle Timing Advance IE properly

Move writing Timing Advance IE and Timing Advance Index into separate
functions to simplify adding PTCCH support. This also fixes previous
incorrect (and unused) code for writing Packet TA IE which has not set
TS for TA.

Change-Id: I786bf7fc999d401cc3d9e7f1e7a1fba953b5d458
Related: OS#1545
1 file changed