WIP: xtensa: add Three Core HiFi-2 MX Variant.

Signed-off-by: Pete Delaney <piet@tensilica.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
WIP: xtensa: add SMP support

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: fix __flush_dtlb_all isync/dsync

xtensa ISA says that IDTLB instruction must be separated from the
following translations possibly affected by the invalidation by the
DSYNC instruction, not the ISYNC. Replace ISYNC with DSYNC and rename
invalidate_dtlb_entry_no_isync to invalidate_dtlb_entry_no_dsync.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
WIP: xtensa: add shabu core

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>