ARM: configs: keystone: Add CPU Hotplug related options

Add the config options needed to get CPU hotplug functional.
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>

arch/arm/configs/keystone_defconfig

@@ -30,6 +30,8 @@ CONFIG_PCI=y
 CONFIG_PCI_MSI=y
 CONFIG_PCI_KEYSTONE=y
 CONFIG_SMP=y
+CONFIG_HOTPLUG_CPU=y
+CONFIG_ARM_PSCI=y
 CONFIG_PREEMPT=y
 CONFIG_AEABI=y
 CONFIG_HIGHMEM=y