Doc: Remove useless escape characters

Just like has been done in the porting guide a couple of patches
earlier, kill all escaped underscore characters in all documents.

Change-Id: I7fb5b806412849761d9221a6ce3cbd95ec43d611
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
diff --git a/docs/rt-svc-writers-guide.rst b/docs/rt-svc-writers-guide.rst
index cec2ae7..4d4066c 100644
--- a/docs/rt-svc-writers-guide.rst
+++ b/docs/rt-svc-writers-guide.rst
@@ -91,7 +91,7 @@
 each owning entity can place the implementation of its runtime service. The
 `PSCI`_ implementation is located here in the `lib/psci`_ directory.
 
-Runtime service sources will need to include the `runtime\_svc.h`_ header file.
+Runtime service sources will need to include the `runtime_svc.h`_ header file.
 
 Registering a runtime service
 -----------------------------
@@ -140,7 +140,7 @@
 #. The ``_type`` is one of ``SMC_TYPE_FAST`` or ``SMC_TYPE_YIELD``
 #. ``_setup`` and ``_smch`` routines have been specified
 
-`std\_svc\_setup.c`_ provides an example of registering a runtime service:
+`std_svc_setup.c`_ provides an example of registering a runtime service:
 
 .. code:: c
 
@@ -310,6 +310,6 @@
 .. _Firmware Design: ./firmware-design.rst
 .. _services: ../services
 .. _lib/psci: ../lib/psci
-.. _runtime\_svc.h: ../include/common/runtime_svc.h
+.. _runtime_svc.h: ../include/common/runtime_svc.h
 .. _smccc.h: ../include/lib/smccc.h
-.. _std\_svc\_setup.c: ../services/std_svc/std_svc_setup.c
+.. _std_svc_setup.c: ../services/std_svc/std_svc_setup.c