arm64 syscall.c needs uio.h for struct iovec

Change-Id: I9d070d0e148636be1d9ecec8ec4dfb72f93c4ed6

arch/arm64/kernel/syscall.c

@@ -14,6 +14,7 @@
 #include <prctl.h>
 #include <limits.h>
 #include <syscall.h>
+#include <uio.h>
 #include <debug.h>
 
 extern void ptrace_report_signal(struct thread *thread, int sig);