ARM: scu: add empty scu_enable for !CONFIG_SMP

Add an empty version of scu_enable for !SMP builds. This fixes
compile error for highbank suspend code on !SMP builds.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>

arch/arm/include/asm/smp_scu.h

@@ -7,8 +7,14 @@
 
 #ifndef __ASSEMBLER__
 unsigned int scu_get_core_count(void __iomem *);
-void scu_enable(void __iomem *);
 int scu_power_mode(void __iomem *, unsigned int);
+
+#ifdef CONFIG_SMP
+void scu_enable(void __iomem *scu_base);
+#else
+static inline void scu_enable(void __iomem *scu_base) {}
+#endif
+
 #endif
 
 #endif