The TF-M include directory for the AN555 is required when
building TF-M for the MPS3-FPGA running the AN555
application note which is also referred as the
`SSE-310-MPS3_FPGA`.

Additionally, ensure the utility module that
implement serial connection for the platform
is also added to the build when building for
the FPGA.

Signed-off-by: Ahmed.Ismail <Ahmed.Ismail@arm.com>