net/bnxt: fix usage of VMDq flags

Map ETH_VMDQ_ACCEPT_HASH_UC to the promiscuous bit.
Also, set ALLMULTI and MCAST when MCAST is set to ensure multicast traffic
is received regardless of the VF driver list.

Fixes: 4cfe399f6550 ("net/bnxt: support to set VF rxmode")
Cc: stable@dpdk.org
Signed-off-by: Stephen Hurd <stephen.hurd@broadcom.com>
Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>