Fix incorrect ABI settings in FP-capable simulation configurations.

Created by: zchamski

This allows the linking of correct libgcc version for tests that require libgcc support.

• cva6.py (load_config): Change ABI to FP-capable ones for all ISA configs that have floating-point extension(s) enabled.

Signed-off-by: Zbigniew Chamski zbigniew.chamski@thalesgroup.com