wil6210: ethtool ops

Provide ethtool support; with support for interrupt coalescing through
get_coalesce/set_coalesce.
Placeholders for begin/complete will be used by runtime PM
to make sure target is powered up while performing ethtool operations

Change-Id: Ie9435e2bec192e269c6539ab47b206c407611ad3
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Git-commit: b6b1b0ec05889951747b6f22dcb0220f3cc2e9e0
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-testing.git


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