tools: Ignore option for circular_includes script

Added an "ignore" argument to the circular_includes script. This
allows the caller to specify files for the script to ignore when
it parses the source file. Rather than creating a special
ignore case for "kernel_all.c" in the script itself, the user
parses the file as an argument (plus others if needed). Updated
the kernels cmake file to reflect the change.

tools: fix licenses

tools: Make circular_includes check more robust

Allows for an arbitrary path to be applied to kernel_all.c in case the build is not
happening in the current working directory

Replace circular includes perl script with python