xtensa: wire up sched_setattr and sched_getattr syscalls

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/include/uapi/asm/unistd.h

@@ -734,7 +734,12 @@ __SYSCALL(332, sys_finit_module, 3)
 #define __NR_accept4				333
 __SYSCALL(333, sys_accept4, 4)
 
-#define __NR_syscall_count			334
+#define __NR_sched_setattr			334
+__SYSCALL(334, sys_sched_setattr, 2)
+#define __NR_sched_getattr			335
+__SYSCALL(335, sys_sched_getattr, 3)
+
+#define __NR_syscall_count			336
 
 /*
  * sysxtensa syscall handler