Import AMD Piledriver DGEMM kernel generated by AUGEM.
So far, this kernel doesn't deal with edge.

AUGEM: Automatically Generate High Performance Dense Linear Algebra
Kernels on x86 CPUs.
Qian Wang, Xianyi Zhang, Yunquan Zhang, and Qing Yi. In the
International Conference for High Performance Computing, Networking,
Storage and Analysis (SC'13). Denver, CO. Nov, 2013.
added dgemm_kernel for Piledriver
added sgemm_kernel for PILEDRIVER
added zgemm_kernel for Piledriver
added cgemm_kernel for Piledriver
small optimizations on dgemm_kernel for Piledriver
changes for compatibility with Pathscale compiler
changes for compatibility with Pathscale compiler
Merge remote branch 'origin/develop' into bulldozer
merged form develop
merge from develop
Merge remote branch 'origin/develop' into piledriver
Merge remote branch 'origin/bulldozer' into develop
Merge remote branch 'origin/piledriver' into develop