Add support for 32 AXI Data & Address width

[Scheremo]

Introduces support for 32 Bit host system (AXI Addrwidth & Datawidth) with Clusters using 32 Bit Addrwidth and 64 Bit Datawidth.

Added

• narrow_adapter to adapter between 32 Bit and 64 Bit Datawidth domains.

Changed

• Default Cfg now uses 32 Bit AxiDataWidth and 32 Bit AddressWidth Host
• Default Cfg now uses 64 Bit DataWidth and 32 Bit AddressWidth Snitch Clusters. Adjustable via chimera_pkg
• Bumped iDMA commit which fixes incompatibility with mixed 64- and 32-Bit Datawidth systems

Removed

• Removed slink, VGA, USB ports from chimera_top_wrapper
• Removed slink-specific fixture functions

[Scheremo]

LGTM, some minor comments, removes serial link functionality from the VIP and wrapper, but if that's the intention 👍, it should still be around in Cheshire and the top-level in the wrapper anyway.

Yep, we can add it back if/once needed with any issue.