iio: imu: adis16475.c: Remove unused enum elements

Remove unused enum elements ADIS16475_SCAN_DIAG_S_FLAGS and
ADIS16475_SCAN_CRC_FAILURE.

Signed-off-by: Ramona Bolboaca <ramona.bolboaca@analog.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20230719123152.309624-2-ramona.bolboaca@analog.com


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