checkpatch: add printk_once and printk_ratelimit to prefer pr_<level> warning

checkpatch: add printk_once and printk_ratelimit to prefer pr_<level> warning

Add the _once and _ratelimited variants to the test for
printk(KERN_<LEVEL> that should prefer pr_<level>.

Miscellanea:

o Add comment description for the conversions

[joe@perches.com: fixlet]
Link: https://lkml.kernel.org/r/32260871d4718ba7f48a8e9e07452bb76de300db.camel@perches.comLink:
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>