ASoC: rt5677: Add missing voice activation register definitions

Most of the voice activation definitions were missing, they will be
needed for when hotwording is added. Also the source bits are only 2
wide not 3 and needed to be corrected.

Signed-off-by: Curtis Malainey <cujomalainey@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>