ARM: OMAP2+: Fix regression for using local timer on non-SMP SoCs

On am437x we use also an ARM timer in addition to the dmtimer. As am437x
is not an SMP SoC, we need tick_broadcast() implemented. With the recent
dmtimer changes, Arnd started to see link failures for non-SMP am437x
configuration:

kernel/time/tick-broadcast.o: in function `tick_device_uses_broadcast':
tick-broadcast.c:(.text+0x130): undefined reference to `tick_broadcast'

Let's fix the issue by reverting dmtimer related changes that started
building timer.c only for CONFIG_SOC_HAS_REALTIME_COUNTER. We still
always need timer.c built-in for omap5 and dra7 for timer_probe().

And let's also move am437x tick_broadcast() to board-generic.c as
that's where we now call timer_probe() for am437x. This way we avoid
adding back more ifdefs to timer.c.

Fixes: 2ee04b8854 ("ARM: OMAP2+: Drop old timer code for dmtimer and 32k counter")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/mach-omap2/timer.c

@@ -39,6 +39,8 @@
 #define INCREMENTER_DENUMERATOR_RELOAD_OFFSET		0x14
 #define NUMERATOR_DENUMERATOR_MASK			0xfffff000
 
+#ifdef CONFIG_SOC_HAS_REALTIME_COUNTER
+
 static unsigned long arch_timer_freq;
 
 void set_cntfreq(void)
@@ -46,14 +48,6 @@ void set_cntfreq(void)
 	omap_smc1(OMAP5_DRA7_MON_SET_CNTFRQ_INDEX, arch_timer_freq);
 }
 
-#if !defined(CONFIG_SMP) && defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
-void tick_broadcast(const struct cpumask *mask)
-{
-}
-#endif
-
-#if defined(CONFIG_SOC_OMAP5) || defined(CONFIG_SOC_DRA7XX)
-
 /*
  * The realtime counter also called master counter, is a free-running
  * counter, which is related to real time. It produces the count used
@@ -165,6 +159,14 @@ sysclk1_based:
 	iounmap(base);
 }
 
+#else
+
+static inline void realtime_counter_init(void)
+{
+}
+
+#endif	/* CONFIG_SOC_HAS_REALTIME_COUNTER */
+
 void __init omap5_realtime_timer_init(void)
 {
 	omap_clk_init();
@@ -172,4 +174,3 @@ void __init omap5_realtime_timer_init(void)
 
 	timer_probe();
 }
-#endif /* CONFIG_SOC_OMAP5 || CONFIG_SOC_DRA7XX */