regexdev: add core functions

regexdev: add core functions

This commit introduce the API that is needed by the RegEx devices in
order to work with the RegEX lib.

During the probe of a RegEx device, the device should configure itself,
and allocate the resources it requires.
On completion of the device init, it should call the
rte_regex_dev_register in order to register itself as a RegEx device.

Signed-off-by: Ori Kam <orika@mellanox.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Acked-by: Guy Kaneti <guyk@marvell.com>