refactor(gicv3): rename GIC Clayton to GIC-700

The GIC IP formerly known as "GIC Clayton" has been released under the
name of "GIC-700".

Rename occurences of Clayton in comments and macro names to reflect the
official name.

Change-Id: Ie8c55f7da7753127d58c8382b0033c1b486f7909
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/drivers/arm/gic/v3/gic600_multichip_private.h b/drivers/arm/gic/v3/gic600_multichip_private.h
index fe4134c..27b8e81 100644
--- a/drivers/arm/gic/v3/gic600_multichip_private.h
+++ b/drivers/arm/gic/v3/gic600_multichip_private.h
@@ -28,8 +28,8 @@
 #define GICD_DCHIPR_RT_OWNER_SHIFT	4
 
 /*
- * If GIC v4 extension is enabled, then use SPI macros specific to GIC-Clayton.
- * Other shifts and mask remains same between GIC-600 and GIC-Clayton.
+ * If GIC v4 extension is enabled, then use SPI macros specific to GIC-700.
+ * Other shifts and mask remains same between GIC-600 and GIC-700.
  */
 #if GIC_ENABLE_V4_EXTN
 #define GICD_CHIPRx_SPI_BLOCK_MIN_SHIFT	9