drm/amdkfd: expose num_sdma_queues_per_engine data field to topology node (v2)

Thunk driver would like to know the num_sdma_queues_per_engine data, however
this data relied on different asic specific. So it's better to get it from kfd
driver.

v2: don't update the name size.

Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>