Silicon/ARM/NeoverseN1Soc: Fix missing function documentation

This patch adds missing documentation for few of the functions
and fixes few formatting changes.

Signed-off-by: Khasim Syed Mohammed <khasim.mohammed@arm.com>
Reviewed-by: Pierre Gondois <pierre.gondois@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>