drm/bridge: sii9234: silence warning about regulators during deferred probe

Don't confuse user with meaningless warning about failure in getting
regulators in case of deferred probe.

Signed-off-by: Marek Szyprowski <[e-mail]>
Reviewed-by: Laurent Pinchart <[e-mail]>
Reviewed-by: Krzysztof Kozlowski <[e-mail]>
Signed-off-by: Andrzej Hajda <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/bridge/sii9234.c

···
 	ctx->supplies[3].supply = "cvcc12";
 	ret = devm_regulator_bulk_get(ctx->dev, 4, ctx->supplies);
 	if (ret) {
-		dev_err(ctx->dev, "regulator_bulk failed\n");
+		if (ret != -EPROBE_DEFER)
+			dev_err(ctx->dev, "regulator_bulk failed\n");
 		return ret;
 	}