Specifying unstable coefficients for the low/high pass filters can have
a severe impact on the audio. This patchs adds a stability check on the
coefficients written to the low/high pass filter block to prevent this.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>