qcacmn: Introduce QCA_NL80211_VENDOR_SUBCMD_HANG

Event indicating to the user space that the driver has detected an
internal failure. The driver is expected to recover from such a failure
automatically, e.g., by resetting the device.
This event carries the information indicating the reason that triggered
this detection.

Change-Id: Ia13e6f102e5e18ec4864ed258728369d51a77ff4
CRs-fixed: 2120886
5 files changed