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/mediatek/include/plat.ld.rodata.inc b/plat/mediatek/include/plat.ld.rodata.inc
index 06ad491..e766472 100644
--- a/plat/mediatek/include/plat.ld.rodata.inc
+++ b/plat/mediatek/include/plat.ld.rodata.inc
@@ -25,6 +25,6 @@
 	__MTK_SMC_POOL_END_UNALIGNED__ = .;
 	. = ALIGN(8);
 #include <vendor_pubsub_events.h>
-	*(mtk_plat_ro)
+	*(.mtk_plat_ro)
 
 #endif /* PLAT_LD_RODATA_INC */