DMC500: Add platform support to set system interface count

Some low end platforms using DMC500 memory controller do not have
CCI(Cache Coherent Interconnect) interface and only have non-coherent
system interface support. Hence this patch makes the system interface
count configurable from the platforms.

Change-Id: I6d54c90eb72fd18026c6470c1f7fd26c59dc4b9a
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
diff --git a/include/drivers/arm/tzc_dmc500.h b/include/drivers/arm/tzc_dmc500.h
index 2606d1b..ff58a27 100644
--- a/include/drivers/arm/tzc_dmc500.h
+++ b/include/drivers/arm/tzc_dmc500.h
@@ -130,6 +130,7 @@
 typedef struct tzc_dmc500_driver_data {
 	uintptr_t dmc_base[MAX_DMC_COUNT];
 	int dmc_count;
+	unsigned int sys_if_count;
 } tzc_dmc500_driver_data_t;
 
 void tzc_dmc500_driver_init(const tzc_dmc500_driver_data_t *plat_driver_data);