net: thunderx: Fix configuration of L3/L4 length checking

This patch fixes enabling of HW verification of L3/L4 length and
TCP/UDP checksum which is currently being cleared. Also fixed VLAN
stripping config which is being cleared when multiqset is enabled.

Signed-off-by: Sunil Goutham <sgoutham@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>