fix(gicv3): fixed bug in the initialization of GICv3 SGIs/(E)PPIs interrupt priorities

Default priority was not being set for all interrupts (gicr_write_ipriorityr takes INTID, not register number). The fix makes the loop to pass INTID in range 0, 4, 8, 12, ...

Signed-off-by: Sylwester Garncarek <sylwester.garncarek@sciopta.com>
Change-Id: Iaa975f6af49f5826c2811161f55242844c28ea81
diff --git a/drivers/arm/gic/v3/gicv3_helpers.c b/drivers/arm/gic/v3/gicv3_helpers.c
index 446d0ad..940c939 100644
--- a/drivers/arm/gic/v3/gicv3_helpers.c
+++ b/drivers/arm/gic/v3/gicv3_helpers.c
@@ -253,7 +253,7 @@
 }
 
 /*******************************************************************************
- * Helper function to configure the default attributes of (E)SPIs
+ * Helper function to configure the default attributes of (E)PPIs/SGIs
  ******************************************************************************/
 void gicv3_ppi_sgi_config_defaults(uintptr_t gicr_base)
 {
@@ -292,7 +292,7 @@
 	regs_num = ppi_regs_num << 3;
 	for (i = 0U; i < regs_num; ++i) {
 		/* Setup the default (E)PPI/SGI priorities doing 4 at a time */
-		gicr_write_ipriorityr(gicr_base, i, GICD_IPRIORITYR_DEF_VAL);
+		gicr_write_ipriorityr(gicr_base, i << 2, GICD_IPRIORITYR_DEF_VAL);
 	}
 
 	/* 16 interrupt IDs per GICR_ICFGR register */