Add support to initialize imu for gfx v11.
IMU is a new power management block for
gfx which manages gfx power.
Signed-off-by: NLikun Gao <Likun.Gao@amd.com>
Reviewed-by: NHawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>