ethdev: add packet type range function

ethdev: add packet type range function

Add `rte_eth_dev_set_ptypes` function that will allow the application
to inform the PMD about reduced range of packet types to handle.
Based on the ptypes set PMDs can optimize their Rx path.

-If application doesn’t want any ptype information it can call
`rte_eth_dev_set_ptypes(ethdev_id, RTE_PTYPE_UNKNOWN, NULL, 0)`
and PMD may skip packet type processing and set rte_mbuf::packet_type to
RTE_PTYPE_UNKNOWN.

-If application doesn’t call `rte_eth_dev_set_ptypes` PMD can return
`rte_mbuf::packet_type` with `rte_eth_dev_get_supported_ptypes`.

-If application is interested only in L2/L3 layer, it can inform the PMD
to update `rte_mbuf::packet_type` with L2/L3 ptype by calling
`rte_eth_dev_set_ptypes(ethdev_id,
		RTE_PTYPE_L2_MASK | RTE_PTYPE_L3_MASK, NULL, 0)`.

Suggested-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Signed-off-by: Pavan Nikhilesh <pbhagavatula@marvell.com>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>