n1sdp: remote chip SPI numbering for multichip GIC routing

Allocated 512-959 SPI numbers for remote n1sdp chip and same has been
referenced for GIC routing table.

Change-Id: Id79ea493fd665ed93fe9644a59e363ec10441098
Signed-off-by: Sayanta Pattanayak <sayanta.pattanayak@arm.com>

plat/arm/board/n1sdp/n1sdp_bl31_setup.c

@@ -63,8 +63,8 @@ static struct gic600_multichip_data n1sdp_multichip_data __init = {
 		PLAT_ARM_GICD_BASE >> 16
 	},
 	.spi_ids = {
-		{32, 255},
-		{0, 0}
+		{32, 479},
+		{512, 959}
 	}
 };