GitLab

It is needed to make it appear in the table of contents. Right now,
all Amlogic documentation pages appear under the "Platform ports"
section, except the AXG one.

Change-Id: Ibcfc3b156888d2a9574953578978b629e185c708
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>