Calling amdgpu_device_ip_resume_phase1() during shutdown leaves the
HW in an active state and is an unbalanced use of the IP callbacks.

Using the IP callbacks like this can lead to memory leaks, double
free and imbalanced reference counters.

Leaving the HW in an active state can lead to DMA accesses to memory now
freed by the driver.

Both is a complete no-go for driver unload so completely revert the
workaround for now.

This reverts commit f5c7e779.
Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>