these files are really Makefiles, so complaining about tabs in them is
counterproductive.
the regexp will catch debian.rules as well, which is the convention
found in obs.

Change-Id: I4487a964468f2d3fbf3cad9c91be06ebfdcfaefb
Reviewed-by: Sergio Ahumada <sergio.ahumada@nokia.com>
Reviewed-by: Rohan McGovern <rohan.mcgovern@nokia.com>