Build: Convert fvp_sse300 target to modern cmake

Add cmake files to mps2/fvp_sse300 target directory. Alter scatter files to
remove preprocessor shebang. Alter header files where include paths have
changed.

WARNING: This change will not build in isolation, it requires _all_
other cmake changes to successfully build. It is split out only for ease
of understanding.

Signed-off-by: Marton Berke <marton.berke@arm.com>
Signed-off-by: Anton Komlev <anton.komlev@arm.com>
Change-Id: I18158967fb1dff1e7adf4f4ac8ea003989ff717a
6 files changed