firmware: imx: scu-pd: decouple the SS information from domain names

As resource power domain service is provided by SCU firmware, no
SS information required. So we can remove the SS indicator from
the domain names, then the domains defined can be better shared
among different SCU based platforms.

Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: linux-pm@vger.kernel.org
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>