plat/arm/sgi: add support for SGI-Clark platform

SGI-Clark platform is the next version in the Arm's SGI platform
series. One of the primary difference between the SGI-575 platform and
the SGI-Clark platform is the MHU version (MHUv2 in case of SGI-Clark).
Add the required base support for SGI-Clark platform.

Change-Id: If396e5279fdf801d586662dad0b55195e81371e4
Signed-off-by: Chandni Cherukuri <chandni.cherukuri@arm.com>
diff --git a/plat/arm/css/sgi/include/sgi_variant.h b/plat/arm/css/sgi/include/sgi_variant.h
index 5698d0a..dea580b 100644
--- a/plat/arm/css/sgi/include/sgi_variant.h
+++ b/plat/arm/css/sgi/include/sgi_variant.h
@@ -4,10 +4,21 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#ifndef __SGI_VARIANT_H__
-#define __SGI_VARIANT_H__
+#ifndef SGI_VARIANT_H
+#define SGI_VARIANT_H
 
 /* SSC_VERSION values for SGI575 */
 #define SGI575_SSC_VER_PART_NUM		0x0783
 
-#endif /* __SGI_VARIANT_H__ */
+/* SID Version values for SGI-Clark */
+#define SGI_CLARK_SID_VER_PART_NUM		0x0786
+
+/* Structure containing SGI platform variant information */
+typedef struct sgi_platform_info {
+	unsigned int platform_id;	/* Part Number of the platform */
+	unsigned int config_id;		/* Config Id of the platform */
+} sgi_platform_info_t;
+
+extern sgi_platform_info_t sgi_plat_info;
+
+#endif /* SGI_VARIANT_H */