Add vdsm build with libfapi support

- added an option to allow specifying custom patches when building the src.rpm
  on mock
- build vdsm adding gluster libfapi support

Change-Id: I77f97ebe66ce4c7bcaad97d55fd73edf3464c480
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>