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/rockchip/common/aarch32/plat_helpers.S b/plat/rockchip/common/aarch32/plat_helpers.S
index 475c297..9f49cbd 100644
--- a/plat/rockchip/common/aarch32/plat_helpers.S
+++ b/plat/rockchip/common/aarch32/plat_helpers.S
@@ -151,7 +151,7 @@
 	 * Per-CPU Secure entry point - resume or power up
 	 * --------------------------------------------------------------------
 	 */
-	.section tzfw_coherent_mem, "a"
+	.section .tzfw_coherent_mem, "a"
 	.align  3
 cpuson_entry_point:
 	.rept	PLATFORM_CORE_COUNT