svga: restrict use of rawbuf for constant buffer access to GL43 device

Restrict use of rawbuf for constant buffer access to GL43 capable
device only.

Fixes glretrace regressions running with SW Renderer.

Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Zack Rusin <zackr@vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25381>

src/gallium/drivers/svga/svga_resource_buffer_upload.c

@@ -209,6 +209,7 @@ svga_buffer_create_host_surface(struct svga_screen *ss,
           */
          sbuf->key.coherent = ss->sws->have_coherent;
 
+         if (ss->sws->have_gl43) {
             /* Set the persistent bit so if the buffer is to be bound
              * as constant buffer, we'll access it as raw buffer
              * instead of copying the content back and forth between the
@@ -224,6 +225,7 @@ svga_buffer_create_host_surface(struct svga_screen *ss,
                sbuf->key.flags |= SVGA3D_SURFACE_BIND_RAW_VIEWS;
             }
          }
+      }
 
       sbuf->key.size.width = sbuf->b.width0;
       sbuf->key.size.height = 1;