use zephyr.h as the main include in applications, no need to have nano/micro
includes in applications and samples.
Inclusion of the proper kernel headers is be handled in the zephyr.h based
on the configured and used kernel.
Change-Id: If5275cef5d2ad1f475dfb39102cb71cfe5630f6c
Signed-off-by: Anas Nashif <anas.nashif@intel.com>