feat(sve): add helper routines to read, write, compare SVE registers

Add helper routines to read, write, write_rand and compare SVE
Z, P, FFR registers.

These helper routines can be called by testcases running in NS-EL2,
R-EL1, S-EL1 payload. The caller has to configure SVE vector length and
has to pass memory to read/write SVE registers.

Signed-off-by: Arunachalam Ganapathy <arunachalam.ganapathy@arm.com>
Change-Id: I3fa064c76a498ee2348d92cba2544a6e50331e15
4 files changed