auxdisplay: fix broken menu

Having the CHARLCD Kconfig symbol between "menuconfig AUXDISPLAY"
and "if AUXDISPLAY" breaks the AUXDISPLAY submenus, so move the
CHARLCD Kconfig symbol near the end of the file so that the menu
display is continuous.

Also include ARM_CHARLCD inside of the if AUXDISPLAY/endif block.
Geert says that it should be there.

Fixes: 39f8ea46 ("auxdisplay: charlcd: Extract character LCD core from misc/panel")

Cc: stable@vger.kernel.org # v4.12
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>