Revert "drm/radeon: Implement radeon_pci_shutdown"

This causes a race condition between drm_dev_unregister()
and pci_driver.shutdown at shutdown or driver unload time.

We need to revisit how to properly support kexec within
the drm.

This reverts commit 846ae41ae99d314bf2a02784152208a6ddf7eddc.
1 file changed