d2-common: remove unused init.qcom.coex.sh

Change-Id: Ia4fe6b75725702582e1cd3f85cd0929b0dc387a4
d2-common: update startup scripts for 4.3

Patch set 2: rebased
Patch set 3: added a missing bit, and reverted changes to dhcpd_bnep0
that broke bt tethering

Change-Id: I31efbc59be7faf0fde595e55f6647101ea392841
Merge changes I31efbc59,Ia4fe6b75 into jb4.3

* changes:
  d2-common: update startup scripts for 4.3
  d2-common: remove unused init.qcom.coex.sh