ARM: OMAP2+: Fix sar_base inititalization for HS omaps

HS omaps use irq_save_secure_context() instead of irq_save_context()
so sar_base will never get initialized and irq_sar_clear() gets called
with a wrong address for HS omaps from irq_restore_context().

Starting with commit f4b9f40ae9 ("ARM: OMAP4+: Initialize SAR RAM
base early for proper CPU1 reset for kexec") we have it available,
and this ideally would been fixed with that commit already.

Fixes: f4b9f40ae9 ("ARM: OMAP4+: Initialize SAR RAM base early for
proper CPU1 reset for kexec")
Cc: Andrew F. Davis <afd@ti.com>
Cc: Dave Gerlach <d-gerlach@ti.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/omap-wakeupgen.c

@@ -299,8 +299,6 @@ static void irq_save_context(void)
 	if (soc_is_dra7xx())
 		return;
 
-	if (!sar_base)
-		sar_base = omap4_get_sar_ram_base();
 	if (wakeupgen_ops && wakeupgen_ops->save_context)
 		wakeupgen_ops->save_context();
 }
@@ -598,6 +596,8 @@ static int __init wakeupgen_init(struct device_node *node,
 	irq_hotplug_init();
 	irq_pm_init();
 
+	sar_base = omap4_get_sar_ram_base();
+
 	return 0;
 }
 IRQCHIP_DECLARE(ti_wakeupgen, "ti,omap4-wugen-mpu", wakeupgen_init);