gallium: Remove vc4 simulator hack from loader infrastructure.

Now that there's MESA_LOADER_DRIVER_OVERRIDE for choosing the driver name
we load, we don't need this any more.

v2: Get the junk out of pipe_loader_drm.c, too.

Reviewed-by: Emil Velikov <emil.velikov@collabora.com> (v1)
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com> (v2)

src/gallium/auxiliary/pipe-loader/pipe_loader_drm.c

@@ -93,17 +93,6 @@ static const struct drm_driver_descriptor driver_descriptors[] = {
         .create_screen = pipe_i915_create_screen,
         .configuration = configuration_query,
     },
-#ifdef USE_VC4_SIMULATOR
-    /* VC4 simulator and ILO (i965) are mutually exclusive (error at
-     * configure). As the latter is unconditionally added, keep this one above
-     * it.
-     */
-    {
-        .driver_name = "i965",
-        .create_screen = pipe_vc4_create_screen,
-        .configuration = configuration_query,
-    },
-#endif
     {
         .driver_name = "nouveau",
         .create_screen = pipe_nouveau_create_screen,

src/gallium/targets/dri/target.c

@@ -73,16 +73,6 @@ DEFINE_LOADER_DRM_ENTRYPOINT(virtio_gpu)
 
 #if defined(GALLIUM_VC4)
 DEFINE_LOADER_DRM_ENTRYPOINT(vc4)
-
-#if defined(USE_VC4_SIMULATOR)
-/**
- * When building using the simulator (on x86), we advertise ourselves as the
- * i965 driver so that you can just make a directory with a link from
- * i965_dri.so to the built vc4_dri.so, and point LIBGL_DRIVERS_PATH to that
- * on your i965-using host to run the driver under simulation.
- */
-DEFINE_LOADER_DRM_ENTRYPOINT(i965)
-#endif
 #endif
 
 #if defined(GALLIUM_ETNAVIV)