auxdisplay: Add HD44780 Character LCD support

The Hitachi HD44780 Character LCD Controller is commonly used on
character LCDs that can display one or more lines of text.

This driver supports character LCDs connected to GPIOs, using either a
4-bit or 8-bit data bus, and provides access through the charlcd core
and /dev/lcd.

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