DO NOT MERGE ANYWHERE hal: Implement Tx mute in ASM loopback am: 666786ddcb  -s ours am: 1ac36f79aa  -s ours am: f10797ba87  -s ours
am: 28aece0ed6  -s ours

Change-Id: Iee8594060084327ed0642ec2bb9680f16df73061