dpdk: enable CPU feature detection.

This commit implements a method to retrieve the CPU ISA capabilities.
These ISA capabilities can be used in OVS to at runtime select a function
implementation to make the best use of the available ISA on the CPU.

Signed-off-by: Harry van Haaren <harry.van.haaren@intel.com>
Acked-by: William Tu <u9012063@gmail.com>
Signed-off-by: Ian Stokes <ian.stokes@intel.com>

lib/dpdk-stub.c

@@ -79,6 +79,15 @@ print_dpdk_version(void)
 {
 }
 
+bool
+dpdk_get_cpu_has_isa(const char *arch OVS_UNUSED,
+                     const char *feature OVS_UNUSED)
+{
+    VLOG_ERR_ONCE("DPDK not supported in this version of Open vSwitch, "
+                  "cannot use CPU flag based optimizations");
+    return false;
+}
+
 void
 dpdk_status(const struct ovsrec_open_vswitch *cfg)
 {