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/mt8173/drivers/spm/spm.c b/plat/mediatek/mt8173/drivers/spm/spm.c
index 1caab3b..8980e07 100644
--- a/plat/mediatek/mt8173/drivers/spm/spm.c
+++ b/plat/mediatek/mt8173/drivers/spm/spm.c
@@ -29,9 +29,9 @@
 
 DEFINE_BAKERY_LOCK(spm_lock);
 
-static int spm_hotplug_ready __section("tzfw_coherent_mem");
-static int spm_mcdi_ready __section("tzfw_coherent_mem");
-static int spm_suspend_ready __section("tzfw_coherent_mem");
+static int spm_hotplug_ready __section(".tzfw_coherent_mem");
+static int spm_mcdi_ready __section(".tzfw_coherent_mem");
+static int spm_suspend_ready __section(".tzfw_coherent_mem");
 
 void spm_lock_init(void)
 {