ath10k: add support for hardware rfkill

ath10k: add support for hardware rfkill

When hardware rfkill is enabled in the firmware it will report the
capability via using WMI_TLV_SYS_CAP_INFO_RFKILL bit in the WMI_SERVICE_READY
event to the host. ath10k will check the capability, and if it is enabled then
ath10k will set the GPIO information to firmware using WMI_PDEV_SET_PARAM. When
the firmware detects hardware rfkill is enabled by the user, it will report it
via WMI_RFKILL_STATE_CHANGE_EVENTID. Once ath10k receives the event it will
send wmi command WMI_PDEV_SET_PARAM to the firmware to enable/disable the radio
and also notifies cfg80211.

We can't power off the device when rfkill is enabled, as otherwise the
firmware would not be able to detect GPIO changes and report them to the
host. So when rfkill is enabled, we need to keep the firmware running.

Tested with QCA6174 PCI with firmware
WLAN.RM.4.4.1-00109-QCARMSWPZ-1.

Signed-off-by: Alan Liu <alanliu@codeaurora.org>
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>