staging: samsung-laptop: Extend samsung-laptop platform driver to sup…

…port another flavor of its platform BIOS.

There are currently two implementations of the Samsung BIOS that controls the rfkill
switch, backlight brightness / power and performance level. The samsung-laptop driver
implements the BIOS flavor with the SECLINUX signature, this patch implements talking
to the other BIOS with 'SwSmi@' signature. Both expose very similar functionality and
way of accessing the commands. The differences are mostly offsets, command identifiers
and some values.

This patch introduces a sabi_config structure that contains information on identifying
and accessing specific SABI flavors.

Signed-off-by: Ingmar Steen <iksteen@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>