net/cnxk: support multicast filter

net/cnxk: support multicast filter

Patch adds multicast filter support for cn9k and cn10k platforms.

CGX DMAC filter table(32 entries) is divided among all LMACs
connected to it i.e. if CGX has 4 LMACs then each LMAC can have
up to 8 filters. If CGX has 1 LMAC then it can have up to 32
filters.

Above mentioned filter table is used to install unicast and multicast
DMAC address filters. Unicast filters are installed via
rte_eth_dev_mac_addr_add API while multicast filters are installed
via rte_eth_dev_set_mc_addr_list API.

So in total, supported MAC filters are equal to DMAC filters plus
mcast filters.

Signed-off-by: Sunil Kumar Kori <skori@marvell.com>