Add sysroot(s) for the ATCA boards

Description

The main blocking point for ATCA compatibility (X2O and APEX) is the absence of sysroot images, including the required dependencies, at least lmdb, log4cplus, and xerces-c (other libraries may be missing).

Find the X2O and APEX sysroot(s), make sure they are complete, and prepare the build instructions (mainly understand the compiler to be used).