Cache invalidation macros use cache line size to iterate over
invalidated cache lines, assuming that all cache ways are invalidated by
single instruction, but xtensa ISA recommends to not assume that for
future compatibility:
  In some implementations all ways at index Addry-1..z are invalidated
  regardless of the specified way, but for future compatibility this
  behavior should not be assumed.

Iterate over all cache ways in ___invalidate_icache_all and
___invalidate_dcache_all.

Cc: stable@vger.kernel.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>