feat(plat/mediatek/build_helpers): introduce mtk makefile

In order to modularize software libraries and platform drivers,
we create makefile helpers to treat a folder as a basic compile

Each module has a build rule (rules.mk) to describe driver and software
library source codes to be built in.

Signed-off-by: Leon Chen <leon.chen@mediatek.com>
Change-Id: Ib2113b259dc97937b7295b265509025b43b14077
4 files changed