Add FEAT_BF16 CPU feature check for tests using BFloat16
Signed-off-by:Anton Bondarenko <anton.bondarenko@arm.com> Approved-by:
Jakub Sujak <jakub.sujak@arm.com>
Signed-off-by:Anton Bondarenko <anton.bondarenko@arm.com> Approved-by:
Jakub Sujak <jakub.sujak@arm.com>