Details:
- Implemented zaxpyf kernel with fuse factor=4 for zgemv.
- Modified BLAS interface call for zgemv to reduce framework overhead.
- Directed gemv to dotv in the case where dimension of y vector is 1.
- when alpha = 0, gemv becomes scalv of Y with beta. Added code to
return early after scaling Y vector with beta.
AMD-Internal: [CPUPL-1402]
Change-Id: I2231285fe3060982d4434466346a040b7ab803fc