arm64: vexpress: Add support for poweroff/restart

This patch adds the arm_pm_poweroff definition expected by the
vexpress-poweroff.c driver and enables the latter for arm64.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pawel Moll <pawel.moll@arm.com>
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index c05bb21..43b0e9f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -32,6 +32,8 @@
 	select OF
 	select OF_EARLY_FLATTREE
 	select PERF_USE_VMALLOC
+	select POWER_RESET
+	select POWER_SUPPLY
 	select RTC_LIB
 	select SPARSE_IRQ
 	select SYSCTL_EXCEPTION_TRACE
@@ -106,6 +108,7 @@
 	bool "ARMv8 software model (Versatile Express)"
 	select ARCH_REQUIRE_GPIOLIB
 	select COMMON_CLK_VERSATILE
+	select POWER_RESET_VEXPRESS
 	select VEXPRESS_CONFIG
 	help
 	  This enables support for the ARMv8 software model (Versatile