container-files/rd-infra-*: add ninja-build to dependency list

The SCP firmware supports both Ninja and GNU Make build systems. So, add
ninja-build to the list of dependencies to build the image.

Signed-off-by: Shriram K <shriram.k@arm.com>
Change-Id: I3ba76f17b9858e5d20c921bcad85f55f05e3a6ab