arm: vexpress64: Enable SYSRESET and SYSRESET_PSCI

Select SYSRESET on Vexpress64 to enable system reset to support other
features, such as capsule-on-disk. Select SYSRESET_PSCI if PSCI is
inferred from the firmware (via ARM_PSCI_FW).
Select ARM_SMCCC for Vexpress64 boards which in turn selects
ARM_PSCI_FW.

The sysreset uclass unconditionally implements a reset_cpu() function.
Remove the empty reset_cpu() in vexpress64 board code.

Signed-off-by: Debbie Horsfall <debbie.horsfall@arm.com>

arch/arm/Kconfig

@@ -1418,6 +1418,8 @@ config ARCH_VEXPRESS64
 	select MTD_NOR_FLASH if MTD
 	select FLASH_CFI_DRIVER if MTD
 	select ENV_IS_IN_FLASH if MTD
+	select SYSRESET
+	select SYSRESET_PSCI if ARM_PSCI_FW
 	imply DISTRO_DEFAULTS
 
 config TARGET_CORSTONE1000

board/armltd/vexpress64/Kconfig

@@ -23,6 +23,7 @@ config VEXPRESS64_BASE_MODEL
 	select POSITION_INDEPENDENT
 	imply DM_RNG
 	imply RNG_ARM_RNDR
+	select ARM_SMCCC
 
 choice
 	prompt "VExpress64 board variant"
@@ -48,6 +49,7 @@ config TARGET_VEXPRESS64_JUNO
 	select USB_EHCI_GENERIC if USB
 	select USB_OHCI_HCD if USB
 	select USB_OHCI_GENERIC if USB
+	select ARM_SMCCC
 	imply OF_HAS_PRIOR_STAGE
 
 endchoice

board/armltd/vexpress64/vexpress64.c

@@ -206,11 +206,6 @@ int board_fdt_blob_setup(void **fdtp)
 #endif
 #endif
 
-/* Actual reset is done via PSCI. */
-void reset_cpu(void)
-{
-}
-
 /*
  * Board specific ethernet initialization routine.
  */