checkpatch: add a placeholder to check blank lines before declarations

Figure out first how to determine if this is in a struct declaration or in
a function body before enabling this.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: c4a62ef9102bfa39f3bb89be2ae1ae11a23ebe28
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>