configs: am62x_evm_a53_defconfig: Disable semi-functional PSCI reset support

At this point, system shutdown is not supported by the DM firmware
that TF-A calls. As we can't de-select only this feature[1], declare
complete PSCI reset support as non-functional so that we don't signal
incomplete support to the OS via EFI runtime services. This makes
power-off under Linux work again when booting via EFI.

[1] https://uefi.org/specs/UEFI/2.9_A/08_Services_Runtime_Services.html?highlight=efiresetshutdown#resetsystem
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
diff --git a/configs/am62x_evm_a53_defconfig b/configs/am62x_evm_a53_defconfig
index 1121256..a2729c1 100644
--- a/configs/am62x_evm_a53_defconfig
+++ b/configs/am62x_evm_a53_defconfig
@@ -25,6 +25,7 @@
 CONFIG_SPL_LIBDISK_SUPPORT=y
 CONFIG_SPL_SPI_FLASH_SUPPORT=y
 CONFIG_SPL_SPI=y
+# CONFIG_PSCI_RESET is not set
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
 CONFIG_SPL_LOAD_FIT=y
 CONFIG_SPL_LOAD_FIT_ADDRESS=0x81000000