Enable acceleration engines (AEs) and accelerators based on soft straps
and fuses. When looping with a number of AEs or accelerators, ignore the
ones that are disabled.

This patch is based on earlier work done by Conor McLoughlin.
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Fiona Trahe <fiona.trahe@intel.com>
Reviewed-by: Wojciech Ziemba <wojciech.ziemba@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>