ext: mcux: Update README to follow template format
ext: mcux: Update README to follow template format

A template for documenting non-apache licensed components was introduced
after mcux was originally imported. Update the README to follow the
template in doc/contribute/code_component_README.

Signed-off-by: Maureen Helm <87a696db5547fa477bda9f9e0f00013c839c14d3@nxp.com>

nashif/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,explora26/zephyr,finikorg/zephyr,punitvara/zephyr,GiulianoFranchetto/zephyr,zephyriot/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,mbolivar/zephyr,ldts/zephyr,punitvara/zephyr,Vudentz/zephyr,punitvara/zephyr,galak/zephyr,kraj/zephyr,punitvara/zephyr,zephyrproject-rtos/zephyr,kraj/zephyr,finikorg/zephyr,ldts/zephyr,galak/zephyr,GiulianoFranchetto/zephyr,ldts/zephyr,finikorg/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,Vudentz/zephyr,zephyriot/zephyr,zephyriot/zephyr,zephyrproject-rtos/zephyr,nashif/zephyr,galak/zephyr,ldts/zephyr,ldts/zephyr,Vudentz/zephyr,nashif/zephyr,kraj/zephyr,nashif/zephyr,mbolivar/zephyr,mbolivar/zephyr,zephyriot/zephyr,finikorg/zephyr,kraj/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,kraj/zephyr,zephyriot/zephyr,zephyrproject-rtos/zephyr,mbolivar/zephyr,explora26/zephyr,mbolivar/zephyr,explora26/zephyr