ASoC: stac9766: Remove register paging support

The AC'97 standard defines paging support for the register range 0x60-0x6f.
Meaning registers in this window are mapped to different physical registers
depending on the setting of the page select register (0x24).

The stac9766 implements support for switching between page 0 and page 1
depending on the addressed register. But the driver never accesses any
registers from page 1, in addition page 0 is the page selected by default.

Considering the development history it is unlikely that the driver will see
any new features that require paging support. Removing the paging support
makes transitioning the driver to regmap a bit more straight forward.

The default register value table is update to contain the values from page
0, rather than page 1.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>