DO NOT MERGE ANYWHERE hal: Implement Tx mute in ASM loopback am: 666786ddcb  -s ours am: 1ac36f79aa  -s ours am: f10797ba87  -s ours
am: 9adf0b1894  -s ours

Change-Id: I711564cf215f0bd5453dbc2d1bea01564b608f19