checkpatch: extend check for camel[0-9_]*CASE

checkpatch: extend check for camel[0-9_]*CASE

Linux has some automatically generated macros that can trigger
camelCASE check. This forces checkpatch to only detect the pattern
	[A-Z][a-z]|[a-z][A-Z]
for adjacent case transition.

In OpenOCD we do not have such case, so extend the check to
	[A-Z][0-9_]*[a-z]|[a-z][0-9_]*[A-Z]
and remove the detection of Linux special cases.

Change-Id: I82cb6dc668edbb093f68991337da1f4b933f1fac
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7152
Tested-by: jenkins