Fix build of shader_runner for GLES.

Commit f184de94 (shader_runner: Add lod_bias option to texparameter)
added support for testing the GL_TEXTURE_LOD_BIAS texture parameter to
shader_runner.  However, this feature is only available in desktop GL.
This caused compile errors with GLES.

This patch ifdefs the feature out when building the GLES version of
shader_runner.