[ALPHA] Fix build in alpha_ksyms.c.

arch/alpha/kernel/alpha_ksyms.c

@@ -35,6 +35,9 @@
 #include <asm/cacheflush.h>
 #include <asm/vga.h>
 
+#define __KERNEL_SYSCALLS__
+#include <asm/unistd.h>
+
 extern struct hwrpb_struct *hwrpb;
 extern void dump_thread(struct pt_regs *, struct user *);
 extern spinlock_t rtc_lock;