OpenBLAS

arm: Remove unnecessary files/code

Since softfp code has been added to all required vfp kernels,
the code for auto detection of abi is no longer required.

The option to force softfp ABI on make command line by giving
ARM_SOFTFP_ABI=1 is retained. But there is no need to give this option
anymore.

Also the newly added C versions of 4x4/4x2 gemm/trmm kernels are removed.
These are longer required. Moreover these kernels has bugs.