Build: Create dedicated FP flags for Arm assembler(armasm).

As armasm does not support -mfloat-abi option for armclang to
specify whether to use hardware instructions or software library
functions for floating-point operations, compilation fails and
reports errors. Create a dedicated FP flags for assembler instead
of sharing the same FP flags with armclang.
Note armlink uses the same FP flags as armasm.

Signed-off-by: Chendi Sun <chendi.sun@arm.com>
Change-Id: If98f4accf237051e4bd9e0dee20ff0dce165400d
4 files changed