Add Azteeg X5 GT to supported list (#8185)

* Add Azteeg X5 GT to supported list

Signed-off-by: Alexey Shvetsov <alexxy@gentoo.org>

* Update README.md

README.md

@@ -31,6 +31,7 @@ Marlin 2.0 adds a new abstraction layer so that Marlin can build and run on 32-b
   [Due](https://www.arduino.cc/en/Guide/ArduinoDue), [RAMPS-FD](http://www.reprap.org/wiki/RAMPS-FD), etc.|[SAM3X8E ARM-Cortex M3](http://www.microchip.com/wwwproducts/en/ATsam3x8e)|84MHz|512k|64+32k|3.3V|no
   [Re-ARM](https://www.kickstarter.com/projects/1245051645/re-arm-for-ramps-simple-32-bit-upgrade)|[LPC1768 ARM-Cortex M3](http://www.nxp.com/products/microcontrollers-and-processors/arm-based-processors-and-mcus/lpc-cortex-m-mcus/lpc1700-cortex-m3/512kb-flash-64kb-sram-ethernet-usb-lqfp100-package:LPC1768FBD100)|100MHz|512k|32+16+16k|3.3-5V|no
   [MKS SBASE](http://forums.reprap.org/read.php?13,499322)|LPC1768 ARM-Cortex M3|100MHz|512k|32+16+16k|3.3-5V|no
+  [Azteeg X5 GT](https://www.panucatt.com/azteeg_X5_GT_reprap_3d_printer_controller_p/ax5gt.htm)|LPC1769 ARM-Cortex M3|120MHz|512k|32+16+16k|3.3-5V|no
   [Teensy 3.5](https://www.pjrc.com/store/teensy35.html)|ARM-Cortex M4|120MHz|512k|192k|3.3-5V|yes
   [Teensy 3.6](https://www.pjrc.com/store/teensy36.html)|ARM-Cortex M4|180MHz|1M|256k|3.3V|yes