utils: ABI Compatibility checker

Provide support to compare ABI compatibility between any two git commits
or by a commit and the most recent ancestral tag of that commit.

Tested-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>