wil6210: remove 3-MSI support

In the recent kernel versions, multiple MSI is not well supported.
In particular, it is not supported on x86 and ARM architectures.
Also, internal interrupt handling logic is simpler and
more effective when using single interrupt.

Remove support for 3 MSI, convert module parameter
"use_msi" from int with range [0,1,3] to boolean.

Change-Id: If0fbc96f30371ed1b30b6b5f0686cda680026ada
Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Git-commit: bd2d18b5
Git-repo: https://github.com/kvalo/ath.git


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