mba6x_bl: Add section on warranty to the license

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
mba6x_bl: Unregister the acpi backlight on successful probe

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
mba6x_bl: Various fixes to prepare for upstreaming

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
mba6x_bl: Don't try to restore the LP8550 on resume

The firmware deals with this for us so nothing is needed. We keep the
hooks if this changes in future firmware updates.

Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>