amiserial: pack and sort includes

The #include directives are in different places in amiserial:
1) there is no reason for that, and
2) it makes hard to judge what is included and what is not.

Therefore, move all the includes to a single place and sort them.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210714091314.8292-9-jslaby@suse.cz


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>