plat/arm: Add support for SGM775

Add support for System Guidance for Mobile platform SGM775

Change-Id: I2442a50caae8f597e5e5949cd48f695cf75d9653
Signed-off-by: Nariman Poushin <nariman.poushin@linaro.org>
diff --git a/plat/arm/css/sgm/sgm_bl1_setup.c b/plat/arm/css/sgm/sgm_bl1_setup.c
new file mode 100644
index 0000000..51e3e53
--- /dev/null
+++ b/plat/arm/css/sgm/sgm_bl1_setup.c
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <bl_common.h>
+#include <debug.h>
+#include <plat_arm.h>
+#include <sgm_plat_config.h>
+#include <soc_css.h>
+
+void bl1_early_platform_setup(void)
+{
+	/* Initialize the platform configuration structure */
+	plat_config_init();
+
+	arm_bl1_early_platform_setup();
+
+#if !HW_ASSISTED_COHERENCY
+	/*
+	 * Initialize Interconnect for this cluster during cold boot.
+	 * No need for locks as no other CPU is active.
+	 */
+	plat_arm_interconnect_init();
+	/*
+	 * Enable Interconnect coherency for the primary CPU's cluster.
+	 */
+	plat_arm_interconnect_enter_coherency();
+#endif
+}