mips: Add clock_gettime64 entry point

With the release of Linux 5.1 has been added a new syscall,
clock_gettime64, that provided a 64 bit time value for a specified
clock_ID to make the kernel Y2038 safe on 32 bit architectures.

Update the mips32 specific vDSO library accordingly with what it has
been done for the kernel syscall exposing the clock_gettime64 entry
point.

Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>

arch/mips/vdso/vdso.lds.S

@@ -96,6 +96,9 @@ VERSION
 		__vdso_clock_gettime;
 		__vdso_gettimeofday;
 		__vdso_clock_getres;
+#if _MIPS_SIM != _MIPS_SIM_ABI64
+		__vdso_clock_gettime64;
+#endif
 #endif
 	local: *;
 	};

arch/mips/vdso/vgettimeofday.c

@@ -29,6 +29,12 @@ int __vdso_clock_getres(clockid_t clock_id,
 	return __cvdso_clock_getres_time32(clock_id, res);
 }
 
+int __vdso_clock_gettime64(clockid_t clock,
+			   struct __kernel_timespec *ts)
+{
+	return __cvdso_clock_gettime(clock, ts);
+}
+
 #else
 
 int __vdso_clock_gettime(clockid_t clock,