ASoC: stac9766: fix wrong usage of DECLARE_TLV_DB_LINEAR()

ASoC: stac9766: fix wrong usage of DECLARE_TLV_DB_LINEAR()

As long as reading datasheet of STAC9766/9767, this driver includes wrong
usage of DECLARE_TLV_DB_LINEAR().

In "8.1.2. Master Volume Registers", attenuation of lineout volumes is
represented in 5 bits by -1.5 dB/step from 0 to -46.5 dB. Thus,
'master_tlv' should be dB step representation.

In "8.1.14. Record Gain", gain of volumes is represented in 4 bits by
1.5 dB/step from 0 to 22.5 dB. Thus, 'record_tlv' should be dB step
representation.

In "8.1.5. PC BEEP Volume", attenuation of volume is represented in 4 bits
by -3 dB/step from 0 to 45 dB. Thus, 'beep_tlv' should be dB step
representation.

In "8.1.7. Stereo or Mic Volume" and so on, gain of volumes is represented
in 5 bits by -1.5 dB from 12 to -34.5 dB. Thus, 'mix_tlv' should be dB
step representation.

Totally, current implementation includes misuse of TLV-related macro.

This commit replaces usage of DECLARE_TLV_DB_LINEAR() with
SNDRV_CTL_TLVD_DECLARE_DB_SCALE(), to give proper information to
applications in user land.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Mark Brown <broonie@kernel.org>