arm: juno: Use PSCI based reset

So far the Juno board wasn't implementing reset. Let's just use the
already existing PSCI_RESET based method to avoid any extra code.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/arm/Kconfig

@@ -1167,6 +1167,8 @@ config TARGET_VEXPRESS64_JUNO
 	select OF_BOARD
 	select CLK
 	select DM_SERIAL
+	select ARM_PSCI_FW
+	select PSCI_RESET
 
 config TARGET_LS2080A_EMU
 	bool "Support ls2080a_emu"

board/armltd/vexpress64/vexpress64.c

@@ -139,9 +139,7 @@ void *board_fdt_blob_setup(void)
 }
 #endif
 
-/*
- * Board specific reset that is system reset.
- */
+/* Actual reset is done via PSCI. */
 void reset_cpu(ulong addr)
 {
 }