audio: hal:Rename audiohal library name

At the start, hack was made in bitbake file to
install audio.primary.default.so library in final
image as part of intial LE HAL bringup.
To avoid hack renaming audiohal library name from
audio_primary_default.la to audio.primary.default.la.

Change-Id: If0e64671fb41aef2ca8a7ac40eab413f726ce43f