Now that we've moved the Gen9 GuC blobs to version 32 we have CTB
support on all gens, so no need to restrict the usage to Gen11+.
Note that MMIO communication is still required for CTB initialization.

v2: fix commit message nits (Michal)
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190606224225.14287-1-daniele.ceraolospurio@intel.com