ovs-numa: Add support for cpu-mask configuration.

This commit adds support in ovs-numa module for reading a user
specified cpu mask, which configures the availability of the cores.

The cpu mask has the format of a hex string similar to the EAL '-c
COREMASK' option input or the 'taskset' mask input.  The lowest order
bit corresponds to the first CPU core.  Bit value '1' means the
corresponding core is available.

An upcoming patch will allow user to configure the mask via OVSDB.

Signed-off-by: Alex Wang <alexw@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
dpif-netdev: Allow multi-rx-queue, multi-pmd-thread configuration.

This commits adds the multithreading functionality to OVS dpdk
module.  Users are able to create multiple pmd threads and set
their cpu affinity via specifying the cpu mask string similar
to the EAL '-c COREMASK' option.

Also, the number of rx queues for each dpdk interface is made
configurable to help distribution of rx packets among multiple
pmd threads.

Signed-off-by: Alex Wang <alexw@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>