ASoC: rt1015: remove unneeded variables in rt1015_priv

- `lrck' is only used in .hw_params callback so that it can be local.
- `bclk' is unused.
- `id' is unused.
- `amp_ver' is unused.

Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20201224100607.3006171-6-tzungbi@google.com


Signed-off-by: Mark Brown <broonie@kernel.org>