Fix broken links to various sections across docs

These broken links were found with the help of this command:
$> sphinx-build -M linkcheck . build

A sample broken link is reported as follows:
(line   80) -local-   firmware-design.rst#secure-el1-payloads-and-dispatchers

Change-Id: I5dcefdd4b8040908658115647e957f6c2c5da7c2
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index 630d861..b15ea1b 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -346,16 +346,14 @@
 -  ``GICV2_G0_FOR_EL3``: Unlike GICv3, the GICv2 architecture doesn't have
    inherent support for specific EL3 type interrupts. Setting this build option
    to ``1`` assumes GICv2 *Group 0* interrupts are expected to target EL3, both
-   by `platform abstraction layer`__ and `Interrupt Management Framework`__.
+   by :ref:`platform abstraction layer<platform Interrupt Controller API>` and
+   :ref:`Interrupt Management Framework<Interrupt Management Framework>`.
    This allows GICv2 platforms to enable features requiring EL3 interrupt type.
    This also means that all GICv2 Group 0 interrupts are delivered to EL3, and
    the Secure Payload interrupts needs to be synchronously handed over to Secure
    EL1 for handling. The default value of this option is ``0``, which means the
    Group 0 interrupts are assumed to be handled by Secure EL1.
 
-   .. __: platform-interrupt-controller-API.rst
-   .. __: interrupt-framework-design.rst
-
 -  ``HANDLE_EA_EL3_FIRST``: When set to ``1``, External Aborts and SError
    Interrupts will be always trapped in EL3 i.e. in BL31 at runtime. When set to
    ``0`` (default), these exceptions will be trapped in the current exception