KERNEL_DIR environment variable can be used to configure
and make CAS with custom kernel source path.
Signed-off-by: Adam Rutkowski <adam.j.rutkowski@intel.com>
Functions and macros dependent on different kernel versions are now generated
before compilation basing on current kernel capabilities instead of hardcoding
them for specific kernels.
Signed-off-by: Michal Mielewczyk <michal.mielewczyk@intel.com>