[Feature Request] Add bias support for torchao/experimental ops

[metascroy]

Add support for an optional bias to the weight packing aten ops: https://github.com/pytorch/ao/blob/main/torchao/experimental/ops/linear_8bit_act_xbit_weight/op_linear_8bit_act_xbit_weight_aten.cpp

The underlying kernels already support bias, but it is disabled at the op level: https://github.com/pytorch/ao/blob/main/torchao/experimental/ops/linear_8bit_act_xbit_weight/op_linear_8bit_act_xbit_weight-impl.h#L173

[metascroy]

Address this: https://github.com/pytorch/ao/pull/1652/files/21cef83acf7cc358fb0381a78b247cd36a554798#diff-e241254074fe937d76f23efb01b50845c3c7d65c16e050e026ba4427ac405903R345-R346

[jcaip]

cc @metascroy is this still open or have we landed bias support already?

[metascroy]

cc @metascroy is this still open or have we landed bias support already?

bias support is added. Closing issue.