ASoC: fsl-ssi: Fix bitclock calculation for master mode

According to the datasheet 'pm', 'psr' and 'div2' should never be all 0.
Since commit 541b03ad ("ASoC: fsl_ssi: Fix the incorrect limitation of
the bit clock rate") this can happen, because for some bitclock rates
'pm' = 0 seems to be a valid choice but does not work due to hardware
restrictions. This results into a bad hardware behaviour (slow audio for
example). Feature tested on a i.MX25.

Signed-off-by: Juergen Borleis <jbe@pengutronix.de>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>