Debian's version of OpenGL is called Mesa and it supports normal
OpenGL on armel too, it would not be hardware-accelerated yet though
because there aren't any free drivers for that in Debian. Same goes
for hardware-acceleration of OpenGLES on ARM, no free drivers in
Debian yet. Some reverse engineering projects and free drivers exist
outside of Debian though:
You can install OpenGLES (libgles1-mesa-dev or libgles2-mesa-dev) on
your standard Debian amd64 PC system, try to build your code and
change it until it doesn't fail.
This will be hardware-accelerated and
be easier than messing around with cross-compilers.
Here are some guides for converting OpenGL code to OpenGLES, any
issues you encounter should be fixable by using a search engine