build: always prefix section names with `.`

Some of our specialized sections are not prefixed with the conventional
period. The compiler uses input section names to derive certain other
section names (e.g. `.rela.text`, `.relacpu_ops`), and these can be
difficult to select in linker scripts when there is a lack of a
delimiter.

This change introduces the period prefix to all specialized section
names.

BREAKING-CHANGE: All input and output linker section names have been
 prefixed with the period character, e.g. `cpu_ops` -> `.cpu_ops`.

Change-Id: I51c13c5266d5975fbd944ef4961328e72f82fc1c
Signed-off-by: Chris Kay <chris.kay@arm.com>
diff --git a/bl2u/bl2u.ld.S b/bl2u/bl2u.ld.S
index 0f06dfd..52a925b 100644
--- a/bl2u/bl2u.ld.S
+++ b/bl2u/bl2u.ld.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2023, Arm Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -55,7 +55,7 @@
         __RODATA_END__ = .;
     } >RAM
 #else /* SEPARATE_CODE_AND_RODATA */
-    ro . : {
+    .ro . : {
         __RO_START__ = .;
 
         *bl2u_entrypoint.o(.text*)
@@ -93,9 +93,9 @@
      * not mixed with normal data.  This is required to set up the correct
      * memory attributes for the coherent data page tables.
      */
-    coherent_ram (NOLOAD) : ALIGN(PAGE_SIZE) {
+    .coherent_ram (NOLOAD) : ALIGN(PAGE_SIZE) {
         __COHERENT_RAM_START__ = .;
-        *(tzfw_coherent_mem)
+        *(.tzfw_coherent_mem)
         __COHERENT_RAM_END_UNALIGNED__ = .;
 
         /*