checkpatch: ignore SI unit CamelCase variants like "_uV"

Many existing variable names use SI like variants that should be otherwise
obvious and acceptable.

Whitelist them from the CamelCase message.

Signed-off-by: Joe Perches <joe@perches.com>
Suggested-by: Phil Carmody <phil.carmody@partner.samsung.com>
Acked-by: Phil Carmody <phil.carmody@partner.samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Git-commit: 22735ce857a2d9f4e6eec37c36be3fcf9d21d154
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


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