wimax: debug macros and debug settings for the WiMAX stack

This file contains a simple debug framework that is used in the stack;
it allows the debug level to be controlled at compile-time (so the
debug code is optimized out) and at run-time (for what wasn't compiled
out).

This is eventually going to be moved to use dynamic_printk(). Just
need to find time to do it.

Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>