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>
11 files changed