iio: invensense: remove redundant initialization of variable period

The variable period is being initialized with a value that is never
read, it is being re-assigned a new value later on before it is read.
The initialization is redundant and can be removed.

Cleans up clang scan build warning:
Value stored to 'period' during its initialization is never
read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
Link: https://lore.kernel.org/r/20240106153202.54861-1-colin.i.king@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

iio: make invensense timestamp module generic

Rename common module to inv_sensors_timestamp, add configuration
at init (chip internal clock, acceptable jitter, ...) and update
inv_icm42600 driver integration.

Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20230606162147.79667-4-inv.git-commit@tdk.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>