xen/arm: Use the right GICD register to initialize IRQs routing

Currently IRQs routing is initialized to the wrong register and overwrites
interrupt configuration register (ICFGRn).

Reported-by: Sander Bogaert <sander.bogaert@elis.ugent.be>
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

xen/arch/arm/gic.c

@@ -280,7 +280,7 @@ static void __init gic_dist_init(void)
 
     /* Route all global IRQs to this CPU */
     for ( i = 32; i < gic.lines; i += 4 )
-        GICD[GICD_ICFGR + i / 4] = cpumask;
+        GICD[GICD_ITARGETSR + i / 4] = cpumask;
 
     /* Default priority for global interrupts */
     for ( i = 32; i < gic.lines; i += 4 )