ASoC: Invert speaker enabling behaviour in SmartQ sound driver

The speaker was enabled when the headphone was plugged in, which isn't the
wanted behaviour so correct this.

Signed-off-by: Maurus Cuelenaere <mcuelenaere@gmail.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>