common/cnxk: fix null pointer dereferences

common/cnxk: fix null pointer dereferences

Fix null pointer dereference issues reported by
klockwork(static analysis tool).

Fixes: c045d2e5cbbc ("common/cnxk: add CPT configuration")
Fixes: 585bb3e538f9 ("common/cnxk: add VF support to base device class")
Fixes: 665ff1ccc2c4 ("common/cnxk: add base device class")
Fixes: da57d4589a6f ("common/cnxk: support NIX flow control")
Fixes: 218d022e1f3f ("common/cnxk: support NIX stats")
Fixes: 4efa6e82fe43 ("common/cnxk: support NIX extended stats")
Fixes: 0885429c3028 ("common/cnxk: add NIX TM hierarchy enable/disable")
Cc: stable@dpdk.org
Signed-off-by: Gowrishankar Muthukrishnan <gmuthukrishn@marvell.com>
Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>