drm/i915/uc: Add params for specifying firmware

`guc_firmware_path` and `huc_firmware_path` module parameters are added.

Using the parameter disables version checks and loads desired firmware
instead of the default one.

v2: make params unsafe && notice about disabled fw check (J. Lahtinen)

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/intel_huc.c b/drivers/gpu/drm/i915/intel_huc.c
index ea67abc..ab4ee08 100644
--- a/drivers/gpu/drm/i915/intel_huc.c
+++ b/drivers/gpu/drm/i915/intel_huc.c
@@ -153,7 +153,11 @@ void intel_huc_select_fw(struct intel_huc *huc)
 	huc->fw.load_status = INTEL_UC_FIRMWARE_NONE;
 	huc->fw.fw = INTEL_UC_FW_TYPE_HUC;
 
-	if (IS_SKYLAKE(dev_priv)) {
+	if (i915.huc_firmware_path) {
+		huc->fw.path = i915.huc_firmware_path;
+		huc->fw.major_ver_wanted = 0;
+		huc->fw.minor_ver_wanted = 0;
+	} else if (IS_SKYLAKE(dev_priv)) {
 		huc->fw.path = I915_SKL_HUC_UCODE;
 		huc->fw.major_ver_wanted = SKL_HUC_FW_MAJOR;
 		huc->fw.minor_ver_wanted = SKL_HUC_FW_MINOR;