Now that the env PCI framework already requires enumerating devices
based on an enum of specific device types, it is not useful to query the
class code of a PCI device handle.
It is currently unused and does not work in its current form on FreeBSD
(it reads a file from /sys). This lets us drop a big chunk of file
reading and parsing code.
Change-Id: I1d720398416ba3d6f91e077b807ec11a6de562cf
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>