Now the core implements the work queue, remove it from the drivers,
and switch to using brightness_set_blocking op.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>