intel_idle: Skylake Client Support - updated

Addition of PC9 state, and minor tweaks to existing PC6 and PC8 states.
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/idle/intel_idle.c

@@ -620,7 +620,7 @@ static struct cpuidle_state skl_cstates[] = {
 		.name = "C6-SKL",
 		.desc = "MWAIT 0x20",
 		.flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
-		.exit_latency = 75,
+		.exit_latency = 85,
 		.target_residency = 200,
 		.enter = &intel_idle,
 		.enter_freeze = intel_idle_freeze, },
@@ -636,10 +636,18 @@ static struct cpuidle_state skl_cstates[] = {
 		.name = "C8-SKL",
 		.desc = "MWAIT 0x40",
 		.flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
-		.exit_latency = 174,
+		.exit_latency = 200,
 		.target_residency = 800,
 		.enter = &intel_idle,
 		.enter_freeze = intel_idle_freeze, },
+	{
+		.name = "C9-SKL",
+		.desc = "MWAIT 0x50",
+		.flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
+		.exit_latency = 480,
+		.target_residency = 5000,
+		.enter = &intel_idle,
+		.enter_freeze = intel_idle_freeze, },
 	{
 		.name = "C10-SKL",
 		.desc = "MWAIT 0x60",