Revert "ARM: 8457/1: psci-smp is built only for SMP"

This reverts commit dbcfee72 which is
commit be95485a upstream.

Upstream commit be95485a (ARM: 8457/1: psci-smp is built only for SMP)
was intended to fix the build error for configs with CONFIG_SMP=n and
CONFIG_ARM_PSCI=y, but it end up introducing a build error when
cherry-picked on 3.18.y.

This patch resulted in redefinition of psci_init() and broke the
build for every build config in 3.18.y with CONFIG_SMP=n and
CONFIG_ARM_PSCI=y.
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/arm/include/asm/psci.h

@@ -37,7 +37,7 @@ struct psci_operations {
 extern struct psci_operations psci_ops;
 extern struct smp_operations psci_smp_ops;
 
-#if defined(CONFIG_SMP) && defined(CONFIG_ARM_PSCI)
+#ifdef CONFIG_ARM_PSCI
 int psci_init(void);
 bool psci_smp_available(void);
 #else