hash: check SSE flags only on x86 builds
hash: check SSE flags only on x86 builds

This is necessary because the required CPU flags may not be defined on
other architectures.

Signed-off-by: Cyril Chemparathy <eff9b25a02e40cc8a3060ecfabdb379b97435a4e@ezchip.com>
Signed-off-by: Zhigang Lu <d473c8ac947e53ca706b2148c5db2c971399f855@ezchip.com>
Acked-by: Bruce Richardson <66b9e8e8fbd5e9f41f91b0af050876182ce9d0e4@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,msune/dpdk,tsphillips/dpdk-fork,mixja/dpdk,tsphillips/dpdk-fork,john-mcnamara-intel/dpdk,tsphillips/dpdk-fork,mixja/dpdk,mixja/dpdk,msune/dpdk,venkynv/dpdk-mirror,mixja/dpdk,msune/dpdk,venkynv/dpdk-mirror,venkynv/dpdk-mirror,tsphillips/dpdk-fork,msune/dpdk,venkynv/dpdk-mirror,john-mcnamara-intel/dpdk