ASoC: arizona: Prefer lower FRATIO in pseudo-fractional mode

When setting up an FLL in pseudo-fractional mode it is preferred
to use a lower FRATIO if possible to give a higher reference clock
frequency. This patch swaps the two loops in arizona_calc_fratio()
so that lower FRATIOs are tried first. The decrementing loop is also
changed to start from init_ratio because the original settings might
already give a fractional value for N.K

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>