Add CCN support to FVP platform port

This patch adds support to select CCN driver for FVP during build.
A new build option `FVP_INTERCONNECT_DRIVER` is added to allow
selection between the CCI and CCN driver. Currently only the CCN-502
variant is supported on FVP.

The common ARM CCN platform helper file now verifies the cluster
count declared by platform is equal to the number of root node
masters exported by the ARM Standard platform.

Change-Id: I71d7b4785f8925ed499c153b2e9b9925fcefd57a
diff --git a/plat/arm/board/fvp/include/plat_macros.S b/plat/arm/board/fvp/include/plat_macros.S
index e43c7ac..657a39b 100644
--- a/plat/arm/board/fvp/include/plat_macros.S
+++ b/plat/arm/board/fvp/include/plat_macros.S
@@ -64,7 +64,9 @@
 	mov_imm	x16, VE_GICD_BASE
 print_gic_regs:
 	arm_print_gic_regs
+#if FVP_INTERCONNECT_DRIVER == FVP_CCI
 	print_cci_regs
+#endif
 	.endm
 
 #endif /* __PLAT_MACROS_S__ */