Disable unnecessary vectorization and SVE features for SME kernels

Current solution for SME microkernels support is to use
SME opcodes and SVE instruction in streaming mode. And a precondition
for compiler to understand SVE instructions is compilation with
-march=...+sve+sve2. However this allows compiler to generate own SVE
instructions for normal C/C++ code. And might cause illegal instruction
exception on CPUs where SME implemented w/o SVE. In this case we want
to disable usage of compiler generated SVE instructions.

Test no SVE instructions using FVP with disabled SVE support.

Signed-off-by: Anton Bondarenko <anton.bondarenko@arm.com>

Approved-by: Felix Johnny Thomasmathibalan <felixjohnny.thomasmathibalan@arm.com>