eeepc-laptop: read rfkill soft-blocked state on resume

This will respect state changes over hibernation, e.g. if the user
disables the wireless in the BIOS setup screen.

It reveals an issue where ACPI silently kills the wireless on
suspend.  Normally, the BIOS restores the correct state from
non-volatile storage on boot.  But when hibernation is aborted,
the wireless would remain killed.  Fortunately we can work around
this in the resume handler by simply writing back the same value we
read from NVS.

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>