drm/xe/guc: Bump PVC GuC version to 70.9.1

The PVC GuC version that we're currently using (70.6.4) has a known
issue that leads to dropping the disabling of contexts that have
pending page faults. This is fixed in newer blobs, so we need to
update to a more recent release.

Link: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/696


Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>