drm/amdgpu: add condition check for trace_amdgpu_cs()

v1:
add trace event enabled check to avoid nop loop when submit multi ibs
in amdgpu_cs_ioctl() function.

v2:
add a new wrapper function to trace all amdgpu cs ibs.

Signed-off-by: Kevin Wang <kevin1.wang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>