sony-laptop: no need to unblock rfkill on load

The re-written rfkill core ensures rfkill devices are initialized to
the system default state.  The core calls set_block after registration
so the driver shouldn't need to.

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