drm/i915/huc: Normalize HuC status returned by I915_PARAM_HAS_HUC

In response for I915_PARAM_HAS_HUC we are returning value that
indicates if HuC firmware was loaded and verified. However, our
previously used positive value was based on specific register bit
which is about to change on future platform. Let's normalize our
return values to 0 and 1 before clients will start to use Gen9 value.

v2: use bool for implicit conversion (Chris)
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Haihao Xiang <haihao.xiang@intel.com>
Reviewed-by: Michał Winiarski <michal.winiarski@intel.com> #1
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20181017195245.39644-1-michal.wajdeczko@intel.com

drivers/gpu/drm/i915/intel_huc.c

@@ -108,13 +108,14 @@ int intel_huc_auth(struct intel_huc *huc)
  * This function reads status register to verify if HuC
  * firmware was successfully loaded.
  *
- * Returns positive value if HuC firmware is loaded and verified
- * and -ENODEV if HuC is not present.
+ * Returns: 1 if HuC firmware is loaded and verified,
+ * 0 if HuC firmware is not loaded and -ENODEV if HuC
+ * is not present on this platform.
  */
 int intel_huc_check_status(struct intel_huc *huc)
 {
 	struct drm_i915_private *dev_priv = huc_to_i915(huc);
-	u32 status;
+	bool status;
 
 	if (!HAS_HUC(dev_priv))
 		return -ENODEV;