ARM: OMAP2+: Fix warning for omap_init_time_of()

Fix warning: no previous prototype for 'omap_init_time_of'.

Fixes: e69b4e1a ("ARM: OMAP2+: Add omap_init_time_of()")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/board-generic.c

@@ -33,7 +33,7 @@ static void __init __maybe_unused omap_generic_init(void)
 }
 
 /* Clocks are needed early, see drivers/clocksource for the rest */
-void __init __maybe_unused omap_init_time_of(void)
+static void __init __maybe_unused omap_init_time_of(void)
 {
 	omap_clk_init();
 	timer_probe();