LU-8789 build: add files to .gitignore

Exclude files that are generated during the "make" build process.

Test-Parameters: trivial

Change-Id: I5a573d7842fec94616de5d016cc5aab99e813193
Signed-off-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-on: https://review.whamcloud.com/23540


Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>