Merge latest changes from Cleanflight

Updated the repo with the latest CleanFlight changes, the merge compiled and ran on x86.  I'm in the middle of updating OrangePI buildroot to use some patches from Armbian and start using device tree overlays.  This makes it easier to add I2C etc without changing the orangePI zero DTS. More on that in the next couple of posts.  i.e basic device overlays using uboot via fdt commands.

Cleanflight configurator is working, the imu processing was not enabled, so, now the graphic is now updating.  

Also move the process to a core, using cpu isolation   (via taskset, etc) to reduce jitter.

Also, working on using dnsmasq as a dhcp server with mdev, this allows I/O board to get a IP address and try zeroconfig/DNS-Based Service Discovery.  The goal is to use names, instead of hard coded IP addresses, so when moving to WiFi networking there will not be a conflict.   Confusing?  I'm too ;)

Updated the I/O EEM packet handling to increase the performance, takes about 23us per 64 byte USB packet.  The goal is to have a 512 UDP packet take less then a 1ms. 

Looked at the GPS handling, right now, GPS parsing is handled on the I/O card, tho goal being to reduce processing in the main loop.  Still looking at the code and how RTH and stabilization process the GPS information.

Tasks Order:

• Update Kernel/u-boot to use overlays
• 4.13 kernel is booting along with u-boot (Now)
• updating boot.src to process device tree overlays  (in progress)
• Dynamic IP addressing 
• Test DHCP server first
• Add zeroconfig with MDNS on lwIP 
•  
•  Retest EEM USB Ethernet
• Add LED API 
• Cleanflight uses two LED APIs will use the basic one, i.e 3 LEDs and test the speed of UDP updating LEDs from Linux
• Add PWM reciever API
• The I/O is processing PWM from receiver, will forward this info onto Cleanflight  validate the configurator is working.