feature: add support to required features

[lromor]

Some parts have a some required features that must be always enabled.
Ensure those are enabled when generatin the bitstream.

See:
https://github.com/chipsalliance/f4pga-xc-fasm/blob/25dc605c9c0896204f0c3425b52a332034cf5e5c/xc_fasm/fasm2frames.py#L190
https://github.com/f4pga/prjxray/blob/faf9c774a340e39cf6802d009996ed6016e63521/prjxray/db.py#L108C39-L108C61