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/xilinx/versal_net/versal_net_gicv3.c b/plat/xilinx/versal_net/versal_net_gicv3.c
index 1d45a58..138d2c2 100644
--- a/plat/xilinx/versal_net/versal_net_gicv3.c
+++ b/plat/xilinx/versal_net/versal_net_gicv3.c
@@ -39,8 +39,8 @@
  * We save and restore the GICv3 context on system suspend. Allocate the
  * data in the designated EL3 Secure carve-out memory.
  */
-static gicv3_redist_ctx_t rdist_ctx __section("versal_net_el3_tzc_dram");
-static gicv3_dist_ctx_t dist_ctx __section("versal_net_el3_tzc_dram");
+static gicv3_redist_ctx_t rdist_ctx __section(".versal_net_el3_tzc_dram");
+static gicv3_dist_ctx_t dist_ctx __section(".versal_net_el3_tzc_dram");
 
 /*
  * MPIDR hashing function for translating MPIDRs read from GICR_TYPER register