drm/i915/guc: fix comment about fallback to execlists

We stopped supporting fallback to execlists in commit 121981fafe69
(drm/i915/guc: Combine enable_guc_loading|submission modparams). We
do instead reset and retry in some cases, depending on the workarounds
required by the platform.

Cc: Michal Wajdeczko <[e-mail]>
Cc: Chris Wilson <[e-mail]>
Signed-off-by: Daniele Ceraolo Spurio <[e-mail]>
Reviewed-by: Michal Wajdeczko <[e-mail]>
Signed-off-by: Chris Wilson <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/i915/intel_guc_fw.c

···
 	 * NB: Docs recommend not using the interrupt for completion.
 	 * Measurements indicate this should take no more than 20ms, so a
 	 * timeout here indicates that the GuC has failed and is unusable.
-	 * (Higher levels of the driver will attempt to fall back to
-	 * execlist mode if this happens.)
+	 * (Higher levels of the driver may decide to reset the GuC and
+	 * attempt the ucode load again if this happens.)
 	 */
 	ret = wait_for(guc_ready(guc, &status), 100);
 	DRM_DEBUG_DRIVER("GuC status %#x\n", status);