dtc(1): Update to 97d2d5715eeb45108cc60367fdf6bd5b2046b050

Notable fixes:

• Overlays may now be generated properly without -@
• /__local_fixups__ were not including unit address in their structure
• The error reporting a magic token was misleading, reporting "Bad magic token in header. Got d00dfeed expected 0xd00dfeed" if the token was missing. This has been split out into a separate message.

MFC after: 1 week