drm/amdgpu: modify packet size for pm4 flush tlbs

[Why]
PM4 packet size for flush message was oversized.

[How]
Packet size adjusted to allocate flush + fence packets.

Signed-off-by: Alex Sierra <[email protected]>
Reviewed-by: Christian König <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
4 files changed