Unify type of "cpu_idx" across PSCI module.

NOTE for platform integrators:
   API `plat_psci_stat_get_residency()` third argument
   `last_cpu_idx` is changed from "signed int" to the
   "unsigned int" type.

Issue / Trouble points
1. cpu_idx is used as mix of `unsigned int` and `signed int` in code
with typecasting at some places leading to coverity issues.

2. Underlying platform API's return cpu_idx as `unsigned int`
and comparison is performed with platform specific defines
`PLAFORM_xxx` which is not consistent

Misra Rule 10.4:
The value of a complex expression of integer type may only be cast to
a type that is narrower and of the same signedness as the underlying
type of the expression.

Based on above points, cpu_idx is kept as `unsigned int` to match
the API's and low-level functions and platform defines are updated
where ever required

Signed-off-by: Deepika Bhavnani <deepika.bhavnani@arm.com>
Change-Id: Ib26fd16e420c35527204b126b9b91e8babcc3a5c
diff --git a/lib/psci/psci_stat.c b/lib/psci/psci_stat.c
index 772a184..ecef95a 100644
--- a/lib/psci/psci_stat.c
+++ b/lib/psci/psci_stat.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -28,7 +28,7 @@
  * that goes to power down in non cpu power domains.
  */
 static int last_cpu_in_non_cpu_pd[PSCI_NUM_NON_CPU_PWR_DOMAINS] = {
-		[0 ... PSCI_NUM_NON_CPU_PWR_DOMAINS - 1] = -1};
+		[0 ... PSCI_NUM_NON_CPU_PWR_DOMAINS - 1U] = -1};
 
 /*
  * Following are used to store PSCI STAT values for
@@ -77,7 +77,7 @@
 			const psci_power_state_t *state_info)
 {
 	unsigned int lvl, parent_idx;
-	int cpu_idx = (int) plat_my_core_pos();
+	unsigned int cpu_idx = plat_my_core_pos();
 
 	assert(end_pwrlvl <= PLAT_MAX_PWR_LVL);
 	assert(state_info != NULL);
@@ -94,7 +94,7 @@
 		 * The power domain is entering a low power state, so this is
 		 * the last CPU for this power domain
 		 */
-		last_cpu_in_non_cpu_pd[parent_idx] = cpu_idx;
+		last_cpu_in_non_cpu_pd[parent_idx] = (int)cpu_idx;
 
 		parent_idx = psci_non_cpu_pd_nodes[parent_idx].parent_node;
 	}
@@ -110,7 +110,7 @@
 			const psci_power_state_t *state_info)
 {
 	unsigned int lvl, parent_idx;
-	int cpu_idx = (int) plat_my_core_pos();
+	unsigned int cpu_idx = plat_my_core_pos();
 	int stat_idx;
 	plat_local_state_t local_state;
 	u_register_t residency;
@@ -150,7 +150,7 @@
 
 		/* Call into platform interface to calculate residency. */
 		residency = plat_psci_stat_get_residency(lvl, state_info,
-					last_cpu_in_non_cpu_pd[parent_idx]);
+			(unsigned int)last_cpu_in_non_cpu_pd[parent_idx]);
 
 		/* Initialize back to reset value */
 		last_cpu_in_non_cpu_pd[parent_idx] = -1;