[ALSA] ASoC - Bit clock matching error

This patch by Philipp Zabel fixes a bug whereby the BCLK matching fails
when the Codec BCLK is constant and the CPU BCLK is based upon a
divider.

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>