Revert "Restrict pmsg use to eng builds."

This reverts commit f894b96a9211dcefb83b175720b53a2e49b8e463.

Kernel binaries have incorporated the performance-enhanced pmsg driver
that has removed the bounce buffer.

Bug: 31057326
Bug: 30375418
Change-Id: Id6cec3ac144f57e8e5465aa48bbdc829cf29e283
1 file changed