wil6210: Fix IP version indication for Tx csum offload

Bit DMA_CFG_DESC_TX_OFFLOAD_CFG_L3T_IPV4_POS should be set for IPv4
only. Don't set it for IPv6

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Git-commit: df2d08eed2a38cee971b3f2ff132d8369471404e
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Liron Kuch <lkuch@codeaurora.org>