ARM: export rtc_lock for nvram driver

The rtc_lock is used by both the nvram and rtc drivers, so
we need to export it if at least one of the two is built,
not just for the rtc driver.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/kernel/time.c

@@ -39,13 +39,11 @@
  */
 static struct sys_timer *system_timer;
 
-#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE)
+#if defined(CONFIG_RTC_DRV_CMOS) || defined(CONFIG_RTC_DRV_CMOS_MODULE) || \
+    defined(CONFIG_NVRAM) || defined(CONFIG_NVRAM_MODULE)
 /* this needs a better home */
 DEFINE_SPINLOCK(rtc_lock);
-
-#ifdef CONFIG_RTC_DRV_CMOS_MODULE
 EXPORT_SYMBOL(rtc_lock);
-#endif
 #endif	/* pc-style 'CMOS' RTC support */
 
 /* change this if you have some constant time drift */