drm/radeon: remove global vm lock

Not needed any more.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

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

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

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

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

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