By naming all board declaration (previously in base/include/drivers/board) the
same way, and putting them in platform-specific include-pathes, we save additional
declaration redirection in the base-hw kernel, and in driver definitions.
This patch introduces the functions 'affinity' and 'num_cpus' to the CPU
session interface. The interface extension will allow the assignment of
individual threads to CPUs. At this point, it is just a stub with no
actual platform support.