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/plat/arm/board/arm_fpga/build_axf.ld.S b/plat/arm/board/arm_fpga/build_axf.ld.S
index d8254e5..bd3d163 100644
--- a/plat/arm/board/arm_fpga/build_axf.ld.S
+++ b/plat/arm/board/arm_fpga/build_axf.ld.S
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, ARM Limited. All rights reserved.
+ * Copyright (c) 2023, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  *
@@ -46,7 +46,7 @@
 		KEEP(*(.kern_tramp))
 	}
 
-	/DISCARD/ : { *(stacks) }
+	/DISCARD/ : { *(.stacks) }
 	/DISCARD/ : { *(.debug_*) }
 	/DISCARD/ : { *(.note*) }
 	/DISCARD/ : { *(.comment*) }