Add support for RAK811 board

[Ebiroll]

Please add something like this, rak811.json
STM32L161 mcu.
https://www.aliexpress.com/store/product/RAK811-LoRa-Tracker-Board-MAX-7Q-GPS-Module-and-MEMS-Sensor-Wireless-Remote-Positioning-Solution-LoRaWAN/2805180_32844470946.html?spm=2114.12010608.0.0.219c103eDASa9w

I think earlier versions of the board only had 16K ram so stm32l15xx6.ld is maybe better as ldscript.
{
"build": {
"core": "stm32",
"cpu": "cortex-m3",
"extra_flags": "-DSTM32L151xB -DSTM32L151CBU6",
"hwids": [
[
"0x0429",
"0x0003"
],
[
"0x0429",
"0x0004"
]
],
"f_cpu": "32768000L",
"mcu": "stm32l151cbu6",
"variant": "stm32l151xba",
"ldscript": "/home/olof/rak/STM32L151XBA_FLASH.ld"
},
"frameworks": [
"mbed",
"cmsis"
],
"name": "Rak811",
"upload": {
"maximum_ram_size": 32768,
"maximum_size": 128000
},
"url": "http://www.rakwireless.com/en/download/RAK811/Hardware%20Design",
"vendor": "RAK"
}

Linker script, https://github.com/RAKWireless/RAK811_BreakBoard/blob/master/src/boards/RAK811BreakBoard/cmsis/arm-gcc/STM32L151XBA_FLASH.ld

stm32flash /dev/ttyUSB0
stm32flash 0.5
http://stm32flash.sourceforge.net/

Interface serial_posix: 57600 8E1
Version : 0x31
Option 1 : 0x00
Option 2 : 0x00
Device ID : 0x0429 (STM32L1xxx6(8/B)A)

• RAM : 32KiB (4096b reserved by bootloader)
• Flash : 128KiB (size first sector: 16x256)
• Option RAM : 32b
• System RAM : 4KiB

Here is source,
https://github.com/RAKWireless/RAK811_BreakBoard

[sabas1080]

I am trying to port the RAK811 to the Arduino Core, but I am having some problems wanting to use the module Lora with the Lmic (https://github.com/mcci-catena/arduino-lmic) or Lora (https://github.com/sandeepmistry/arduino-LoRa) libraries with pins RADIO_RF_CRX_RX PB_6 //CRF3 (ANT_SWITCH_TX_BOOST), RADIO_RF_CBT_HF PB_7 //CRF2 HF (ANT_SWITCH_TX_RFO, RADIO_RF_CTX_PA , any help is welcome

stm32duino/Arduino_Core_STM32#229

[ivankravets]

Resolved in f37b7c1