ARM: mach-omap2: board-generic: fix undefined symbol

Since dra7 reuses the  function 'omap5_realtime_timer_init' in
arch/arm/mach-omap2/board-generic.c as timer init function, it has to be
built for this SoC as well.
Signed-off-by: Simon Barth <Simon.Pe.Barth@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/timer.c

@@ -628,7 +628,7 @@ void __init omap4_local_timer_init(void)
 #endif /* CONFIG_HAVE_ARM_TWD */
 #endif /* CONFIG_ARCH_OMAP4 */
 
-#ifdef CONFIG_SOC_OMAP5
+#if defined(CONFIG_SOC_OMAP5) || defined(CONFIG_SOC_DRA7XX)
 void __init omap5_realtime_timer_init(void)
 {
 	omap4_sync32k_timer_init();
@@ -636,7 +636,7 @@ void __init omap5_realtime_timer_init(void)
 
 	clocksource_of_init();
 }
-#endif /* CONFIG_SOC_OMAP5 */
+#endif /* CONFIG_SOC_OMAP5 || CONFIG_SOC_DRA7XX */
 
 /**
  * omap_timer_init - build and register timer device with an