lib/vdso: Cleanup clock mode storage leftovers

Now that all architectures are converted to use the generic storage the
helpers and conditionals can be removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.470699892@linutronix.de

include/linux/clocksource.h

@@ -24,13 +24,13 @@ struct clocksource;
 struct module;
 
 #if defined(CONFIG_ARCH_CLOCKSOURCE_DATA) || \
-    defined(CONFIG_GENERIC_VDSO_CLOCK_MODE)
+    defined(CONFIG_GENERIC_GETTIMEOFDAY)
 #include <asm/clocksource.h>
 #endif
 
 enum vdso_clock_mode {
 	VDSO_CLOCKMODE_NONE,
-#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+#ifdef CONFIG_GENERIC_GETTIMEOFDAY
 	VDSO_ARCH_CLOCKMODES,
 #endif
 	VDSO_CLOCKMODE_MAX,