i915 has nicely collected command macros in one file. We want to use
this pattern (file) and remove duplicated definitions. Unfortunately
command file uses includes which don't exists in userspace, so we
need to import minimal set of kernel includes to ensure we will have
verbatim copy in the future.

v2: Add comment about origin of linux/bitops.h file (Kamil)
    Provide local _AC() macro to avoid other const.h include (Kamil)

Signed-off-by: Zbigniew Kempczyński <zbigniew.kempczynski@intel.com>
Cc: Petri Latvala <adrinael@adrinael.net>
Cc: Kamil Konieczny <kamil.konieczny@linux.intel.com>
Reviewed-by: Kamil Konieczny <kamil.konieczny@linux.intel.com>