iio: adc: mcp3564: drop redundant open-coded spi_get_device_match_data()

The driver calls spi_get_device_match_data() and on its failure calls
again parts of it: spi_get_device_id() and getting driver data.  This is
entirely redundant, because it is part of spi_get_device_match_data().

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240606-spi-match-data-v1-8-320b291ee1fe@linaro.org


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>