MAINTAINERS: add "B:" for URI where to file bugs

Different subsystems and drivers have different preferences for where to
file bugs and what information to include.  Add "B:" entry for
specifying the URI for the bug tracker directly, a web page for detailed
info on filing bugs, or a mailto: URI.

Link: http://lkml.kernel.org/r/1476966135-26943-1-git-send-email-jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Acked-by: Daniel Vetter <daniel@ffwll.ch>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS

@@ -74,6 +74,8 @@ Descriptions of section entries:
 	   These reviewers should be CCed on patches.
 	L: Mailing list that is relevant to this area
 	W: Web-page with status/info
+	B: URI for where to file bugs. A web-page with detailed bug
+	   filing info, a direct bug tracker link, or a mailto: URI.
 	Q: Patchwork web based patch tracking system site
 	T: SCM tree type and location.
 	   Type is one of: git, hg, quilt, stgit, topgit