Possibility to obtain 2 UARTs on B524/B404x

[rickkas7]

SC16IS7xxRK hardware SPI and I2C hardware UART library

This library supports the SC16IS740, SC16IS750, SC16IS760 single UART and SC16IS752, SC16IS762 dual hardware UART chips. Additionally you can add multiple chips to a single SPI or I2C bus for even more ports. This is a great way to add additional hardware UARTs, especially to nRF52 devices which only have a single available UART. The new library fixes several design limitations of the SC16IS740RK library: Support for dual-port chips Buffered read mode uses threads and buffer of user-defined …