ARM: 8689/1: scu: add missing errno include

Add missing errno include to make the header self-contained and avoid
compilation breakage when compiling shared code without
CONFIG_HAVE_ARM_SCU.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/include/asm/smp_scu.h

@@ -7,6 +7,7 @@
 
 #ifndef __ASSEMBLER__
 
+#include <linux/errno.h>
 #include <asm/cputype.h>
 
 static inline bool scu_a9_has_base(void)