Support for varying BOM/SCPI protocol base addresses in ARM platforms

Current code assumes `SCP_COM_SHARED_MEM_BASE` as the base address
for BOM/SCPI protocol between AP<->SCP on all CSS platforms. To
cater for future ARM platforms this is made platform specific.
Similarly, the bit shifts of `SCP_BOOT_CONFIG_ADDR` are also made
platform specific.

Change-Id: Ie8866c167abf0229a37b3c72576917f085c142e8
diff --git a/plat/arm/css/common/css_scp_bootloader.c b/plat/arm/css/common/css_scp_bootloader.c
index c01f42f..8bfaa87 100644
--- a/plat/arm/css/common/css_scp_bootloader.c
+++ b/plat/arm/css/common/css_scp_bootloader.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2015, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2014-2016, ARM Limited and Contributors. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -60,7 +60,7 @@
  * Unlike the SCPI protocol, the boot protocol uses the same memory region
  * for both AP -> SCP and SCP -> AP transfers; define the address of this...
  */
-#define BOM_SHARED_MEM		SCP_COM_SHARED_MEM_BASE
+#define BOM_SHARED_MEM		PLAT_CSS_SCP_COM_SHARED_MEM_BASE
 #define BOM_CMD_HEADER		((bom_cmd_t *) BOM_SHARED_MEM)
 #define BOM_CMD_PAYLOAD		((void *) (BOM_SHARED_MEM + sizeof(bom_cmd_t)))