apmd: fix build with static libraries disabled

apmd: fix build with static libraries disabled

apmd was using foo.o in Makefile dependencies but if libtool is being used then
those are the statically linked intermediate files.  When static libraries are
globally disabled they won't be generated by libtool-cross so the build fails.
Instead, use the libtool intermediate wrapper .lo files so the build succeeds.

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