Revert "config: Changes for libfmjni bp conversion"

This reverts commit d6777fa8.
Reason for revert: The soong namespaces can be removed after reworking
libfmjni to use select() with filegroups and header libs for qcom/slsi.
Broadcom is not used in any recent shipping device and mtk can continue
using prebuilt for now.

Change-Id: I078b321c7c55c3d7e5cd97e2664208c3d44f513a