amdgpu: remove active_rb_pipes from amdgpu_gpu_info

The active RB pipes can be retrieved from enabled_rb_pipes_mask,
for which each bit indicates one active pipe if it is '1'.

Signed-off-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
2 files changed