* Add Microchip SAM series MCU support for RT-Thread

Add Microchip SAM series MCU support for RT-Thread, including SAM Cortex-M0+, M4F and M7.

* Add bsp directory to ignored check list

Add bsp directory to ignored check list, add microchip /samc21/same54/same70 to workflows list

* remove STDIO definition and bug fix

1. remove STDIO code from Microchip official BSP. 2. bug fix of SAME70 hpl/hpl_usart.c, samc21&same54 hpl/hpl_sercom.c baudrate update interface.  3. Add RT-Thread standard STDIO implementation on Microchip SAM MCU.

* add CAN driver & example and script fix

Add CAN driver and example for SAMC21/SAME5x/SAME70 and fix rtconfig.py issue(unused space might result link error)

* Add Chinese version README

Add Chinese version README for SAMC21/E54/E70