drivers: firmware: psci: use const and __initconst for psci_cpuidle_ops

The psci_cpuidle_ops structures is not over-written, so add "const"
qualifier and replace __initdata with __initconst.
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/firmware/psci.c

@@ -355,7 +355,7 @@ int psci_cpu_suspend_enter(unsigned long index)
 
 /* ARM specific CPU idle operations */
 #ifdef CONFIG_ARM
-static struct cpuidle_ops psci_cpuidle_ops __initdata = {
+static const struct cpuidle_ops psci_cpuidle_ops __initconst = {
 	.suspend = psci_cpu_suspend_enter,
 	.init = psci_dt_cpu_init_idle,
 };