iio: imu: icm42600: convert to use maple tree register cache

iio: imu: icm42600: convert to use maple tree register cache

The maple tree register cache is based on a much more modern data structure
than the rbtree cache and makes optimisation choices which are probably
more appropriate for modern systems than those made by the rbtree cache.

Signed-off-by: chuguangqing <chuguangqing@inspur.com>
Acked-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
Link: https://patch.msgid.link/20250611085838.4761-7-chuguangqing@inspur.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>