version 6:
- add an ION bus so heap are show as devices in /sys/bus/ion/
instead of platform bus.
- split the patch in two: one for include reordering and one
for per heap device change
- rebased on top of next-2017110 tag
version 5:
- create a configuration flag to keep legacy Ion misc
version 6:
- add platform_bus and platform_bus_type when register Ion devices
to make them appear in /sys/devices/platform.
- re-order include files in aphabetic order.
version 5:
- create a configuration flag to keep legacy Ion misc device
version 4:
- add a configuration flag to switch
