drivers: sensor: icm42605: fix arg passing bug in trigger thread

the device data struct pointer is passed to the thread function when
creating the thread, but the thread function did a int-to-pointer cast
which did not work as intended, causing exception during runtime.

now, we just pass the pointer directly without casting, which is the
pattern seen in other sensor drivers.

Signed-off-by: Mikkel Jakobsen <mikkel.aunsbjerg@escolifesciences.com>