feat(sve): enable SVE tests in tftf

Adding two tests to check that floating point context is preserved.
1. Use SIMD instructions on SVE-enabled system.
2. Use SVE instruction on a full-length vectors.
Both tests check that floating point context is preserved after
returning from the secure world.

Signed-off-by: Max Shvetsov <maksims.svecovs@arm.com>
Change-Id: Idccff7c3f1658cc66b64e144cc00cda6e0aeea50
7 files changed