config: shorten code for x86 instruction detection
config: shorten code for x86 instruction detection

Rather than checking flag by flag individually, use a loop to make it
easier to check new flags.

Signed-off-by: Bruce Richardson <66b9e8e8fbd5e9f41f91b0af050876182ce9d0e4@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk