Floss: enable LC3 as a SW codec in HFP

In this CL, we enable LC3 SW path codec in HFP.

Note that this feature is not enabled in CrOS at the moment, and Android
does not use SW path as of now.

Bug: 269970706
Tag: #floss
Test: Build and verify
Change-Id: Idf426b36f775d23f510a90d1cf0cf868a25aaf9b