Generate version strings like the PF driver does. This gives us more
flexibility to add suffixes to the version string at build time.

Change-ID: I0a5ca0783dd8fb849516bfc1e37ea070127847bd
Signed-off-by: NMitch Williams <mitch.a.williams@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>