misc: panel: Move all suboptions into a big if section

All 18 suboptions related to the panel driver have individual
dependencies on PANEL.

Replace them by a single "if PANEL / endif # PANEL" section for easier
dependency management.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>