wil6210: support for "sparrow" hardware

New hardware release appears; it require some changes to properly support  it.
Introduce struct wil_board and "board" attribute in wil6210_priv;
keep hardware variant information in this structure.
fill it on probe(). Used in the reset flow.

Change-Id: Ibd51c99fd153e5f3c18c496644485b00382f3b53
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Git-commit: 6508281b0b15c469a940ffa46bb9215c9e18eaf3
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-testing.git


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