Add handling for receiving thermal throttling SMI event from the
kernel.
Also, update the event notification test to work with the new event.
Change-Id: Ib89c12b244f90998ccbae0a38b37f25705d156e0
Event bitmask in KFD SMI event is now replaced with event index in
the SMI event message. Sending a event bitmask, which was a 64-bit
field with only 1 bit set, was quite wasteful of memory and also
potentially limiting to 64 events. Instead the kernel would send
event index in the SMI event message. As a result, update the
KFD SMI event handling to expect the event index in the message.
Change-Id: I3e74620788d3c1f7c0bdaa69e9d9ab3d1aba2c92