drm/bridge: Fix typo in post_disable() description

s/singals/signals/

Fixes: 199e4e96 ("drm: Extract drm_bridge.h")
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231124094253.658064-1-dario.binacchi@amarulasolutions.com

include/drm/drm_bridge.h

@@ -194,7 +194,7 @@ struct drm_bridge_funcs {
 	 * or &drm_encoder_helper_funcs.dpms hook.
 	 *
 	 * The bridge must assume that the display pipe (i.e. clocks and timing
-	 * singals) feeding it is no longer running when this callback is
+	 * signals) feeding it is no longer running when this callback is
 	 * called.
 	 *
 	 * The @post_disable callback is optional.