checkpatch: include/asm checks should be anchored

It is possible to have other include/asm paths within the tree which are
not subject to the do not edit checks.  Ignore those.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>