Added a fix to an issue related to the MUX that by default is not routing the UART1_RX pin to SD3_DAT7 pin of the CPU, causing the software to be unable to receive data from the UART1. Fix contains a new function in the IMX6 MUX API to route the pin to the UART, and the serial initialization code that calls this function (only for the IMX6).

pragma once and for all

Fix whitespace

- remove trailing whitespace
- remove duplicate blank lines
- remove blank lines at end of file

fix licenses