auxdisplay: hd44780_common: Fix build error

When building the hd44780_common driver without a driver that actually
uses it like panel or hd44780 you get a build error, because
hd44780_common uses charlcd, but did not select it. Its users did
select it.

This is fixed now. hd4478_common now selects charlcd in Kconfig and
panel and hd44780 do not. They only select hd44780_common.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>