i915: Add GuC v70.5.1 for DG1, DG2, TGL and ADL-P

Direction from upstream is to use minimal version numbering on
firmware files and replace rather than add. So going forwards, GuC
files will use only the major version number and HuC files will be
completely versionless.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>