Build: Always include preload_ns.cmake if it exists

Rather than using a cmake variable to determine whether to include
preload_ns.cmake, always include it if it exists.

This allows the platforms that currently provide an empty
preload_ns.cmake file to get rid of it.

Change-Id: I7e5755a75133caf7bb3a652a0d4ab2780dc5ae90
Signed-off-by: Chris Brand <chris.brand@cypress.com>
5 files changed