lib/vdso: Build 32 bit specific functions in the right context

clock_gettime32 and clock_getres_time32 should be compiled only with a
32 bit vdso library.

Exclude these symbols when BUILD_VDSO32 is not defined.
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20190830135902.20861-3-vincenzo.frascino@arm.com

lib/vdso/gettimeofday.c

@@ -117,6 +117,7 @@ __cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
 	return 0;
 }
 
+#ifdef BUILD_VDSO32
 static __maybe_unused int
 __cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res)
 {
@@ -139,6 +140,7 @@ __cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res)
 	}
 	return ret;
 }
+#endif /* BUILD_VDSO32 */
 
 static __maybe_unused int
 __cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
@@ -231,6 +233,7 @@ int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res)
 	return 0;
 }
 
+#ifdef BUILD_VDSO32
 static __maybe_unused int
 __cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res)
 {
@@ -253,4 +256,5 @@ __cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res)
 	}
 	return ret;
 }
+#endif /* BUILD_VDSO32 */
 #endif /* VDSO_HAS_CLOCK_GETRES */