pulseaudio: move helper binaries into the relevant module packages

pulseaudio: move helper binaries into the relevant module packages

proximity-helper is only used by the bluetooth-proximity module, and
gconf-helper is only used by the gconf module.  Clarify the packaging and clean
up dependencies by shipping the helper binaries with the modules that spawn
them.

(From OE-Core rev: 039170824cb77c1a68ec91d9f4dc1ae12f701b87)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>