net/bnxt: add initial Rx code

net/bnxt: add initial Rx code

This patch adds initial implementation of rx_pkt_burst() function for Rx.
bnxt_recv_pkts() is the top level function for doing Rx.

This patch also adds code to allocate rings in the ASIC.

For each Rx queue allocated in the PMD driver, a corresponding ring
in hardware will be created. Every time a frame is received a Rx ring
is selected based on the hardware configuration like RSS, MAC or VLAN,
COS and such. The hardware uses a completion ring to indicate the
availability of a packet.

This patch also brings in functions like bnxt_init_one_rx_ring()
bnxt_init_rx_ring_struct() which initializes various structures before
a Rx can begin.

bnxt_init_rxbds() initializes the Rx Buffer Descriptors while
bnxt_alloc_rx_data() allocates a buffer in the host to receive the
incoming packet.

Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Signed-off-by: Stephen Hurd <stephen.hurd@broadcom.com>
Reviewed-by: David Christensen <david.christensen@broadcom.com>