aarch64: entry.S: do not treat all sync aborts as page faults

not all sync aborts are made equal: do not treat everything
as translation faults. For everything else, for now just
put the interesting values in X21..X24 and halt, so that
we can easily debug what happened.

Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
aarch64: libc: remove unnecessary AARCH64_PORT_STUB

The stub implementation is not necessary anymore,
we have mmu and page faults now.

Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
async: remove unused include directive

also remove the AARCH64_PORT_STUB which becomes useless.

Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>
build.mk: fix info message broken by previous commits

Signed-off-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Avi Kivity <avi@cloudius-systems.com>