In fixing an existing patch migration bug, the list of valid extensions
got out of sync from the core patch class. As a result, valid patches
were not being applied to the tree.
Updating the tools to migrate .diff files fixes the issue.
Also in this fix is the removal of .patch in the find_sccs() routine, since
it will never be returned by patch.bbclass when all non-patches are
requested, it is simply confusing.
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>