wil6210: enlarge TX/RX buffer length

HW supports upto 2304 packet size on the air.
HW is responsible for adding (Tx) or removing (Rx) the following headers:
802.11 hdr: 26B
SNAP: 8B
CRC: 4B
Security (optional): 24B
HW adds max 62B to the payload passed from driver. It means driver can use
max packet size of 2304-62 = 2242B

Change-Id: If1c50a8b54ea9d39f86e5e905690453ef5bec8e2
Signed-off-by: Dedy Lansky <qca_dlansky@qca.qualcomm.com>
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Git-commit: e0106adade2dd16fb776f53f25ffe50da0793f3d
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-testing.git


Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>