[Speculative Decoding] Add `norm_before_fc` for gpt-oss draft models (#36545)
Signed-off-by: Shubhra Pandit <shubhra.pandit@gmail.com>
Co-authored-by: Benjamin Chislett <chislett.ben@gmail.com>
Co-authored-by: Benjamin Chislett <bchislett@nvidia.com>