ASoC: arizona: Correct handling of FLL theta in synchroniser mode

Theta/lambda is used to give the fractional portion of the FLL
frequency multiplication. When the synchroniser is active the
reference path lambda value is hard coded in the hardware to
65536. This patch corrects the handling of theta such that it
is scaled to match this denominator, when the synchroniser is
active.

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