dt-bindings: auxdisplay: hit,hd44780: use defines for GPIO flags

Improve example DTS readability by using known defines for GPIO flags.

Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

dt-bindings: auxdisplay: adjust example indentation and use generic node names

The example DTS should be indented with two or four (preferred) spaces,
as mentioned in Writing Schema document. While re-indenting, change the
node names to somehow generic names, as expected by Devicetree
specification.

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ralf Schlatterbeck <rsc@runtux.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

dt-bindings: correct white-spaces in examples

Use only one and exactly one space around '=' in DTS example.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # For MMC
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for-iio
Acked-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20231124092121.16866-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Rob Herring <robh@kernel.org>

auxdisplay: Add I2C gpio expander example

The hd44780 displays are often used with pcf8574 based I/O expanders.
Add example to documentation.

Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Ralf Schlatterbeck <rsc@runtux.com>
[Added Suggested-by tag]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

dt-bindings: auxdisplay: hd44780: Convert to json-schema

Convert the Hitachi HD44780 Character LCD Controller Device Tree binding
documentation to json-schema.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Rob Herring <robh@kernel.org>