fix(plat/qemu): disable PSCI power down support

Currently, Arm Trusted Firmware does not support power-down suspend calls.
This is evident in the implementation of the `qemu_pwr_domain_suspend`
function, which contains an `assert(0)` statement, causing the CPU to
halt indefinitely without recovery.

Signed-off-by: João Peixoto <[email protected]>

Author: joaopeixoto13

src/platform/qemu-aarch64-virt/inc/plat/psci.h

@@ -6,12 +6,14 @@
 #ifndef __PLAT_PSCI_H__
 #define __PLAT_PSCI_H__
 
-#define PSCI_POWER_STATE_LVL_0    0x0000000
-#define PSCI_POWER_STATE_LVL_1    0x1000000
-#define PSCI_POWER_STATE_LVL_2    0x2000000
-#define PSCI_STATE_TYPE_STANDBY   0x1
-#define PSCI_STATE_TYPE_BIT       (1UL << 16)
-#define PSCI_STATE_ID_RETENTION   0x2
-#define PSCI_STATE_TYPE_POWERDOWN PSCI_STATE_TYPE_BIT | PSCI_STATE_ID_RETENTION
+#define PSCI_POWER_STATE_LVL_0            0x0000000
+#define PSCI_POWER_STATE_LVL_1            0x1000000
+#define PSCI_POWER_STATE_LVL_2            0x2000000
+#define PSCI_STATE_TYPE_STANDBY           0x1
+#define PSCI_STATE_TYPE_BIT               (1UL << 16)
+#define PSCI_STATE_ID_RETENTION           0x2
+#define PSCI_STATE_TYPE_POWERDOWN         PSCI_STATE_TYPE_BIT | PSCI_STATE_ID_RETENTION
+
+#define PLAT_PSCI_POWERDOWN_NOT_SUPPORTED 1
 
 #endif // __PLAT_PSCI_H__