wil6210: RX high threshold interrupt configuration

Rx high threshold interrupt is reported by the hardware in case
when number of not utilized by the HW descriptors in the Rx ring
becomes low.
Introduce module parameter for RX high threshold.

Change-Id: I04300ea3505776a5a1fec1277a3d089a9df27c9c
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Git-commit: ab95462825edf7decdd0f77be5c2c1ebb07a1943
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-testing.git


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