scripts: use SPDX tag in get_maintainer and checkpatch

Add the appropriate SPDX tag to these scripts.

Miscellanea:

o Add my copyright to checkpatch

Link: http://lkml.kernel.org/r/d08e49e8f6562c58a63792aa64306d1851f81f4b.camel@perches.com


Signed-off-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>