shared-glapi: Convert to automake

shared-glapi: Convert to automake

This fixes a build problem where EGL links to libgbm.la, which encodes
a relative path to it's libglapi.so dependency.  The relative path
breaks when the linker tries to resolve it from src/egl/main instead
of src/gbm.  Typically we silently fall back to the system
libglapi.so, which is wrong and breaks when there isn't one.

Morale of the story: don't mix mklib and libtool.