The media ranges extend beyond what gen11 gives so we can't piggypack
on gen11 ranges, even on read side.

Introduce a table for gen12 and accessors for it.

v2: correctly implement gen12_fwtable_write/read (Daniele)
v3: update with ranges from bspec.
v4: avoid GEN11_NEEDS_FORCEWAKE (Mika)
v5: bspec ref (Daniele)

BSpec: 52078
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Michel Thierry <michel.thierry@intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190913141652.27958-2-mika.kuoppala@linux.intel.com