ui/gtk-egl: guest fb texture needs to be regenerated when reinitializing egl

ui/gtk-egl: guest fb texture needs to be regenerated when reinitializing egl

If guest fb is backed by dmabuf (blob-resource), the texture bound to the
old context needs to be recreated in case the egl is re-initialized (e.g.
new window for vc is created in case of detaching/reattaching of the tab)

v2: call egl_dmabuf_release_texutre instead of putting 0 to dmabuf->texture
    (Vivek Kasireddy)

Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
Message-Id: <20211104065153.28897-3-dongwon.kim@intel.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>