doc: Format security advisory titles and headings

Required so that the advisory documents are all valid RST files (with a
header) and that they all integrate into the document tree.

Change-Id: I68ca2b0b9e648e24b460deb772c471a38518da26
Signed-off-by: Paul Beesley <paul.beesley@arm.com>
diff --git a/docs/security_advisories/security-advisory-tfv-7.rst b/docs/security_advisories/security-advisory-tfv-7.rst
index 572268a..8e06762 100644
--- a/docs/security_advisories/security-advisory-tfv-7.rst
+++ b/docs/security_advisories/security-advisory-tfv-7.rst
@@ -1,3 +1,6 @@
+Advisory TFV-7 (CVE-2018-3639)
+==============================
+
 +----------------+-------------------------------------------------------------+
 | Title          | Trusted Firmware-A exposure to cache speculation            |
 |                | vulnerability Variant 4                                     |
@@ -46,7 +49,7 @@
 Arm CPUs not mentioned below are unaffected.
 
 Static mitigation
-~~~~~~~~~~~~~~~~~
+-----------------
 
 For affected CPUs, this approach enables the mitigation during EL3
 initialization, following every PE reset. No mechanism is provided to disable
@@ -67,7 +70,7 @@
   (``S3_0_C15_C1_0``).
 
 Dynamic mitigation
-~~~~~~~~~~~~~~~~~~
+------------------
 
 For affected CPUs, this approach also enables the mitigation during EL3
 initialization, following every PE reset. In addition, this approach implements