Switch to use the callback function to poll the reset status on IMU.
Because it will have different sequency on other ASICs.

v2: drop unused variable (Alex)
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>