drm/i915/guc: Expand guc_info debugfs with more information

The information about platform/driver/user view of GuC firmware usage
currently requires user to either go through kernel log or parse the
combination of "enable_guc" modparam and various debugfs entries.
Let's keep things simple and add a "supported/used/wanted" matrix
(already used internally by i915) in guc_info debugfs.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Lukasz Fiedorowicz <lukasz.fiedorowicz@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Lukasz Fiedorowicz <lukasz.fiedorowicz@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200701142752.419878-1-michal@hardline.pl