ARM: 7318/1: gic: refactor irq_start assignment

The irq_start and hwirq_base assignment code is fairly hairy and ended
up being difficult to read following a conflict resolution for 3.2.

This patch rearranges the code slightly to make it easier to read.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/common/gic.c b/arch/arm/common/gic.c
index b2dc2dd..a3bc86f 100644
--- a/arch/arm/common/gic.c
+++ b/arch/arm/common/gic.c
@@ -697,13 +697,12 @@
 	 * For primary GICs, skip over SGIs.
 	 * For secondary GICs, skip over PPIs, too.
 	 */
-	domain->hwirq_base = 32;
-	if (gic_nr == 0) {
-		if ((irq_start & 31) > 0) {
-			domain->hwirq_base = 16;
-			if (irq_start != -1)
-				irq_start = (irq_start & ~31) + 16;
-		}
+	if (gic_nr == 0 && (irq_start & 31) > 0) {
+		domain->hwirq_base = 16;
+		if (irq_start != -1)
+			irq_start = (irq_start & ~31) + 16;
+	} else {
+		domain->hwirq_base = 32;
 	}
 
 	/*