drm/radeon: fix CP semaphores on CIK

The CP semaphore queue on CIK has a bug that triggers if uncompleted
waits use the same address while a signal is still pending. Work around
this by using different addresses for each sync.

Signed-off-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org

diff --cc drivers/gpu/drm/radeon/radeon.h
Simple merge

diff --cc drivers/gpu/drm/radeon/radeon_ring.c
Simple merge

diff --cc drivers/gpu/drm/radeon/radeon_semaphore.c
Simple merge