drm/radeon: allow semaphore emission to fail

To workaround bugs and/or certain limits it's sometimes
useful to fall back to waiting on fences.

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

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

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

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

diff --cc drivers/gpu/drm/radeon/r100.c
Simple merge

diff --cc drivers/gpu/drm/radeon/r600.c
Simple merge

diff --cc drivers/gpu/drm/radeon/r600_dma.c
Simple merge

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

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

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

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

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

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

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

diff --cc drivers/gpu/drm/radeon/rv770_dma.c
Simple merge

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

diff --cc drivers/gpu/drm/radeon/uvd_v1_0.c
Simple merge

diff --cc drivers/gpu/drm/radeon/uvd_v3_1.c
Simple merge