build(bl1): add symbols for memory layout

Add symbols for mapping the physical memory layout of BL1. There are
symbols that partially satisfy this requirement, however, the naming of
these is inconsistent.

Change-Id: I615a7eb28d17e4c2983636ec021124de304573df
Signed-off-by: Harrison Mutai <harrison.mutai@arm.com>

bl1/bl1.ld.S

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2013-2023, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2023, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -24,6 +24,11 @@ MEMORY {
 }
 
 SECTIONS {
+    ROM_REGION_START = ORIGIN(ROM);
+    ROM_REGION_LENGTH = LENGTH(ROM);
+    RAM_REGION_START = ORIGIN(RAM);
+    RAM_REGION_LENGTH = LENGTH(RAM);
+
     . = BL1_RO_BASE;
 
     ASSERT(. == ALIGN(PAGE_SIZE),
@@ -97,6 +102,7 @@ SECTIONS {
     ASSERT(__CPU_OPS_END__ > __CPU_OPS_START__,
         "cpu_ops not defined for this platform.")
 
+    ROM_REGION_END = .;
     . = BL1_RW_BASE;
 
     ASSERT(BL1_RW_BASE == ALIGN(PAGE_SIZE),
@@ -157,4 +163,5 @@ SECTIONS {
 #endif /* USE_COHERENT_MEM */
 
     ASSERT(. <= BL1_RW_LIMIT, "BL1's RW section has exceeded its limit.")
+    RAM_REGION_END = .;
 }