samsung-laptop: ehance SABI support

* SABI command are on 16 bits, not 8
* SABI can read/write up to 11 byte of data
* There is not real difference between "get" and "set"
  commands, so refactorise the code of both functions
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Matthew Garrett <mjg@redhat.com>