freedreno/registers: Handle typed registers with fields

freedreno/registers: Handle typed registers with fields

When a bitset is "inline" it should act as-if the its fields were
inserted into the register itself. However when initializing the
register's bitfield we weren't doing a deep copy of the inline bitfield,
so if the register defined additional fields then they would get added
to the original inline bitfield and any further registers with the same
type would get them. Fix this.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9493>