kernel: remove nano/micro wording and usage

Also remove some old cflags referencing directories that do not exist
anymore.
Also replace references to legacy APIs in doxygen documentation of
various functions.

Change-Id: I8fce3d1fe0f4defc44e6eb0ae09a4863e33a39db
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
30 files changed