checkpatch: add Suggested-by as a standard signature

As people started using Suggested-by as standard signature, adding
"Suggested-by" to the standard signature so that checkpatch won't
generate warning when Suggested-by is used in patch signature
Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/SubmittingPatches

@@ -420,7 +420,7 @@ person it names.  This tag documents that potentially interested parties
 have been included in the discussion
 
 
-14) Using Reported-by:, Tested-by: and Reviewed-by:
+14) Using Reported-by:, Tested-by:, Reviewed-by: and Suggested-by:
 
 If this patch fixes a problem reported by somebody else, consider adding a
 Reported-by: tag to credit the reporter for their contribution.  Please
@@ -468,6 +468,13 @@ done on the patch.  Reviewed-by: tags, when supplied by reviewers known to
 understand the subject area and to perform thorough reviews, will normally
 increase the likelihood of your patch getting into the kernel.
 
+A Suggested-by: tag indicates that the patch idea is suggested by the person
+named and ensures credit to the person for the idea. Please note that this
+tag should not be added without the reporter's permission, especially if the
+idea was not posted in a public forum. That said, if we diligently credit our
+idea reporters, they will, hopefully, be inspired to help us again in the
+future.
+
 
 15) The canonical patch format
 

scripts/checkpatch.pl

@@ -281,6 +281,7 @@ our $signature_tags = qr{(?xi:
 	Tested-by:|
 	Reviewed-by:|
 	Reported-by:|
+	Suggested-by:|
 	To:|
 	Cc:
 )};