xtensa: add seccomp, getrandom, and memfd_create syscalls

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

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

@@ -742,7 +742,14 @@ __SYSCALL(335, sys_sched_getattr, 3)
 #define __NR_renameat2				336
 __SYSCALL(336, sys_renameat2, 5)
 
-#define __NR_syscall_count			337
+#define __NR_seccomp				337
+__SYSCALL(337, sys_seccomp, 3)
+#define __NR_getrandom				338
+__SYSCALL(338, sys_getrandom, 3)
+#define __NR_memfd_create			339
+__SYSCALL(339, sys_memfd_create, 2)
+
+#define __NR_syscall_count			340
 
 /*
  * sysxtensa syscall handler