checkpatch: add logging functions

checkpatch: add logging functions

It's commonly considered that user-visible strings should not be split
to different lines in the sources to ease grepping for them. Hence,
checkpatch traditionally makes an exception for logging functions,
lines having them can be of arbitrary length.

OpenOCD uses different (from Linux, the kernel) names, so they need to
be added to avoid false positives.

This is the old commit bb3cd6ec438d ("checkpatch: add logging functions")
re-applied and updated.

Change-Id: Ib18e4532cf7e1f79821b74c9bb6134a8a4e8be1b
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/5119
Tested-by: jenkins