drm/panel: add connector type to boe,hv070wsa-100 panel

The boe,hv070wsa-100 panel is a LVDS panel.
Fix connector type to reflect this.

With this change users of this panel do not have to specify the
connector type.

v4:
  - Add .bpc = 4 (Laurent)

v3:
  - Drop PIXDATA bus_flag, not relevant

v2:
  - Add .bus_format (Laurent)
  - Add .bus_flags

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200703192417.372164-2-sam@ravnborg.org