Revert "drm/radeon: Fix EEH during kexec"

[ Upstream commit 8d13c187c42e110625d60094668a8f778c092879 ]

This reverts commit 6f7fe9a93e6c09bf988c5059403f5f88e17e21e6.

This breaks some boards.  Maybe just enable this on PPC for
now?

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=205147


Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>