fix(zynqmp): modify conditions to have boolean type

This corrects the MISRA violation C2012-14.4:
The controlling expression of an if statement and the controlling
expression of an iteration-statement shall have essentially
boolean type.
Updated controlling expression to explicitly compare with zero.

Change-Id: I5bf7070db9bced50f5d37a3d9406301585930b50
Signed-off-by: Nithin G <nithing@amd.com>
Signed-off-by: Maheedhar Bollapalli <maheedharsai.bollapalli@amd.com>
diff --git a/plat/xilinx/zynqmp/plat_psci.c b/plat/xilinx/zynqmp/plat_psci.c
index 526e215..2bab7f0 100644
--- a/plat/xilinx/zynqmp/plat_psci.c
+++ b/plat/xilinx/zynqmp/plat_psci.c
@@ -169,7 +169,7 @@
 	pm_system_shutdown(PMF_SHUTDOWN_TYPE_SHUTDOWN,
 			   pm_get_shutdown_scope());
 
-	while (1) {
+	while (true) {
 		wfi();
 	}
 }
@@ -183,7 +183,7 @@
 	pm_system_shutdown(PMF_SHUTDOWN_TYPE_RESET,
 			   pm_get_shutdown_scope());
 
-	while (1) {
+	while (true) {
 		wfi();
 	}
 }
@@ -204,7 +204,7 @@
 		req_state->pwr_domain_state[MPIDR_AFFLVL0] = PLAT_MAX_OFF_STATE;
 	}
 	/* We expect the 'state id' to be zero */
-	if (psci_get_pstate_id(power_state)) {
+	if (psci_get_pstate_id(power_state) != 0U) {
 		return PSCI_E_INVALID_PARAMS;
 	}