patch to fix psci_smp_avaliable build error

[Alex Shi <alex.shi@linaro.org>]

This patch is needed on lts 4.4 for the same build error. Could you like to pick it up?

Regards
Alex
---------
commit be95485a0b8288a93402705730d3ea32f9f812b9
Author: Arnd Bergmann <arnd@arndb.de>
Date:   Thu Nov 19 15:03:57 2015 +0100

    ARM: 8457/1: psci-smp is built only for SMP
    
    The PSCI SMP implementation is built only when both CONFIG_SMP and
    CONFIG_ARM_PSCI are set, so a configuration that has the latter
    but not the former can get a link error when it tries to call
    psci_smp_available().
    
    arch/arm/mach-tegra/built-in.o: In function `tegra114_cpuidle_init':
    cpuidle-tegra114.c:(.init.text+0x52a): undefined reference to `psci_smp_available'
    
    This corrects the #ifdef in the psci.h header file to match the
    Makefile conditional we have for building that function.
    
    Signed-off-by: Arnd Bergmann <arnd@arndb.de>
    Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
index 68ee3ce..b4c6d99 100644
--- a/arch/arm/include/asm/psci.h
+++ b/arch/arm/include/asm/psci.h
@@ -16,7 +16,7 @@
 
 extern struct smp_operations psci_smp_ops;
 
-#ifdef CONFIG_ARM_PSCI
+#if defined(CONFIG_SMP) && defined(CONFIG_ARM_PSCI)
 bool psci_smp_available(void);
 #else
 static inline bool psci_smp_available(void) { return false; }