ipq806x: fix crash on 4.9 if the rpm clock probe happens before cpuidle init

Signed-off-by: Felix Fietkau <nbd@nbd.name>

target/linux/ipq806x/patches-4.9/0070-qcom-spm-fix-probe-order.patch

+Check for SCM availability before attempting to use SPM
+
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+
+--- a/drivers/soc/qcom/spm.c
++++ b/drivers/soc/qcom/spm.c
+@@ -219,6 +219,9 @@ static int __init qcom_cpuidle_init(stru
+ 	cpumask_t mask;
+ 	bool use_scm_power_down = false;
+ 
++	if (!qcom_scm_is_available())
++		return -EPROBE_DEFER;
++
+ 	for (i = 0; ; i++) {
+ 		state_node = of_parse_phandle(cpu_node, "cpu-idle-states", i);
+ 		if (!state_node)