wil6210: prevent deep sleep of 60G device in critical paths

In idle times 60G device can enter deep sleep and turn off
its XTAL clock.
Host access triggers the device power-up flow which will hold
the AHB during XTAL stabilization until device switches from
slow-clock to XTAL clock.
This behavior can stall the PCIe bus for some arbitrary period
of time.
In order to prevent this stall, host can vote for High Latency
Access Policy (HALP) before reading from PCIe bus.
This vote will wakeup the device from deep sleep and prevent
deep sleep until unvote is done.

Change-Id: Ic6bbe8b2aee53d019013159cd21597c2fa0f298f
Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
git-commit: 349214c1e7d718684e19dc3559dffe4e62f55296
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git


CRs-Fixed: 1015627
Signed-off-by: Maya Erez <merez@codeaurora.org>