drm/i915/guc: Fix Gen9 GuC loading workarounds

In commit 4502e9ec ("drm/i915/uc: Unify firmware loading") we
stopped converting errors detected during firmware transfer into
-EAGAIN and this indirectly killed our workarounds for Gen9 GuC.
Reactivate those workarounds by looking for actual -ETIMEDOUT error.

Testcase: igt@drv_selftest@live_hangcheck
Reported-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
References: commit 4502e9ec ("drm/i915/uc: Unify firmware loading")
Signed-off-by: NMichal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: NDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20181016085931.23532-1-michal.wajdeczko@intel.com

drivers/gpu/drm/i915/intel_uc.c

@@ -376,7 +376,7 @@ int intel_uc_init_hw(struct drm_i915_private *i915)
 
 		intel_guc_init_params(guc);
 		ret = intel_guc_fw_upload(guc);
-		if (ret == 0 || ret != -EAGAIN)
+		if (ret == 0 || ret != -ETIMEDOUT)
 			break;
 
 		DRM_DEBUG_DRIVER("GuC fw load failed: %d; will reset and "