mesa: reject immutable textures in glEGLImageTargetTexture2DOES()

mesa: reject immutable textures in glEGLImageTargetTexture2DOES()

GL_ARB_texture_storage says:

    The commands eglBindTexImage, wglBindTexImageARB, glXBindTexImageEXT or
    EGLImageTargetTexture2DOES are not permitted on an immutable-format
    texture.
    They will generate the following errors:
      - EGLImageTargetTexture2DOES: INVALID_OPERATION
      - eglBindTexImage: EGL_BAD_MATCH
      - wglBindTexImage: ERROR_INVALID_OPERATION
      - glXBindTexImageEXT: BadMatch

Fixing the EGL and GLX cases requires extending the DRI interface,
since setTexBuffer2 doesn't currently return any error information.

Reviewed-by: Brian Paul <brianp@vmware.com>