[ogl-sample] gl.spec file missing offset values

[Brian Paul <brianp@xxxxxxxxxxx>]

We want to implement the GL_EXT_secondary_color extension in Mesa.
A number of Mesa/DRI's GL API dispatch files are generated from the
gl.spec file included in the SI (just like the SI generates some
similar files).

Unfortunately, gl.spec (the one in
OGLsample/projects/ogl-sample/main/doc/registry/specs/gl.spec)
does not have 'offset' values assigned to the entrypoints for
GL_EXT_secondary_color.  A bunch of other extensions don't have
offsets assigned either.  We can't generate our dispatch files
without this information.

Can someone fix this, please?

-Brian