net/octeontx2: disable unnecessary error interrupts

Disable CQ_DISABLED error interrupt in NIX_LF_ERR_INT
to fix spurious interrupts in event dev mode. Also skip
configuring RSS when RQ count is '0' because
RSS table initialization is done incorrectly due to
divide-by-zero error and it is leading to RQ_OOR error
in NIX_LF_ERR_INT.

Fixes: 83ce2880e22e ("net/octeontx2: support RSS")
Cc: stable@dpdk.org
Signed-off-by: Nithin Dabilpuram <ndabilpuram@marvell.com>
Acked-by: Jerin Jacob <jerinj@marvell.com>