MIPS: N32: Define getdents64.

As a relativly new ABI N32 should only have received the getdents64(2) but
instead it only had getdents(2).  This was noticed as a performance anomaly
in glibc.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/unistd.h

@@ -984,16 +984,17 @@
 #define __NR_perf_event_open		(__NR_Linux + 296)
 #define __NR_accept4			(__NR_Linux + 297)
 #define __NR_recvmmsg			(__NR_Linux + 298)
+#define __NR_getdents64			(__NR_Linux + 299)
 
 /*
  * Offset of the last N32 flavoured syscall
  */
-#define __NR_Linux_syscalls		298
+#define __NR_Linux_syscalls		299
 
 #endif /* _MIPS_SIM == _MIPS_SIM_NABI32 */
 
 #define __NR_N32_Linux			6000
-#define __NR_N32_Linux_syscalls		298
+#define __NR_N32_Linux_syscalls		299
 
 #ifdef __KERNEL__
 

arch/mips/kernel/scall64-n32.S

@@ -419,4 +419,5 @@ EXPORT(sysn32_call_table)
 	PTR	sys_perf_event_open
 	PTR	sys_accept4
 	PTR     compat_sys_recvmmsg
+	PTR     sys_getdents
 	.size	sysn32_call_table,.-sysn32_call_table