Documentation/SubmittingPatches: remove references to patch-scripts

The link to the tarball for Andrew Morton's patch scripts is dead.
These scripts don't seem to be used for kernel development these days
anyways so just rip out all references to them.

Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>