net/bnxt: fix memzone allocation per VNIC

net/bnxt: fix memzone allocation per VNIC

In case of Thor RSS table size is too big. This could result in
memory allocation failure when the supported vnic count is high.
Instead of allocating the memzone for all VNICs in one shot,
allocate for each VNIC individually.

Also, fixed to free the memzone in the uninit path.

Fixes: 9738793f28ec ("net/bnxt: add VNIC functions and structs")
Cc: stable@dpdk.org
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>