Easy way to configure memory allocation

[rossburton]

As per How do I configure memory use the config should reflect the amount of RAM in the system. We need a nice way to set those Kconfig variables.

[ChinHuatAng]

Not sure if ACRN configuration tool would help: https://drive.google.com/drive/u/0/folders/1Qs8rNHmpKbByqazheU0vyADChIxDLzv8

[cheeyanglee]

this should be able to achieve through customized xml
#97