soc: amlogic: meson-ee-pwrc: propagate PD provider registration errors

of_genpd_add_provider_onecell() can return an error. Propagate the error
so the driver registration fails when of_genpd_add_provider_onecell()
did not work.

Fixes: eef3c2ba0a42a6 ("soc: amlogic: Add support for Everything-Else power domains controller")
Signed-off-by: Martin Blumenstingl <[e-mail]>
Signed-off-by: Kevin Hilman <[e-mail]>

drivers/soc/amlogic/meson-ee-pwrc.c

···
 		pwrc->xlate.domains[i] = &dom->base;
 	}
 
-	of_genpd_add_provider_onecell(pdev->dev.of_node, &pwrc->xlate);
-
-	return 0;
+	return of_genpd_add_provider_onecell(pdev->dev.of_node, &pwrc->xlate);
 }
 
 static void meson_ee_pwrc_shutdown(struct platform_device *pdev)