add sched_{get,set}attr syscall numbers and SCHED_DEADLINE macro

linux 3.14 introduced sched_getattr and sched_setattr syscalls in
commit d50dde5a10f305253cbc3855307f608f8a3c5f73

and the related SCHED_DEADLINE scheduling policy in
commit aab03e05e8f7e26f51dee792beddcb5cca9215a5

but struct sched_attr "extended scheduling parameters data structure"
is not yet exported to userspace (necessary for using the syscalls)
so related uapi definitions are not added yet.

arch/mips/bits/syscall.h

@@ -346,6 +346,8 @@
 #define __NR_process_vm_writev       4346
 #define __NR_kcmp                    4347
 #define __NR_finit_module            4348
+#define __NR_sched_setattr           4349
+#define __NR_sched_getattr           4350
 
 
 /* Repeated with SYS_ prefix */
@@ -697,3 +699,5 @@
 #define SYS_process_vm_writev       4346
 #define SYS_kcmp                    4347
 #define SYS_finit_module            4348
+#define SYS_sched_setattr           4349
+#define SYS_sched_getattr           4350