Test: Enable FP usage in NSPE

1. Enable FP usage in NSPE by adding FP compile option for NS test
   framework and NS library.
2. Add FP test cases in NSPE.

Signed-off-by: Feder Liang <Feder.Liang@arm.com>
Change-Id: I95d97fbfb06e40ef3d4caa5b8f85a52a29c37a46
16 files changed