bif: bif-core: add BIF object matching support

Update the BIF slave matching criteria so that BIF consumer
drivers can find BIF slaves which contain BIF objects of a
certain type.  Also add functions which allow consumers to get
handles for the BIF objects which match specified search
criteria.

Change-Id: Ice7042ecb3829db8f5601d91940c5f7bef383d3d
Signed-off-by: David Collins <collinsd@codeaurora.org>