emulator: opengl: Update/simplify build scripts

This patch is a major rework of the build opengl-emulation
build scripts. See README for details.

In a nutshell, this introduces various functions that considerably
simplify the declaration of the 26+ modules in this implementation,
by handling auto-generation of sources and module imports/exports.

Change-Id: I827522d783c7b6cf5eafd37204a1025c235458cd
29 files changed