ASoC: arizona: Disable free-running mode on FLL1

The free running mode can cause problems when attempting to bring up the
FLL running from a defined clock source. This patch disables
free-running mode.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>