sensors: ICM42688 read/writes chain callbacks

RTIO expects the CHAINED flag to be set when ordering of operations is
important. The callbacks in the icm42688 stream handling were not
chained into, meaning the callbacks would have occured immediately
rather than *after* the SPI reads/writes.

Update all the spi transactions to chain into the desired callbacks in
the driver.

Signed-off-by: Tom Burdick <thomas.burdick@intel.com>