arch: add minimal support for microblaze

The Kernel Test Robot reports a problem on microblaze.

The cause is that __MICROBLAZEEL__ is not defined. However, the real
problem is that sparse has no support at all for this architecture.

So, add the minimal support for microblaze.

Link: https://lore.kernel.org/lkml/202007060542.hNfoTcsC%25lkp@intel.com
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
5 files changed