spi: dt-bindings: sun6i: Allow Dual SPI and Quad SPI for newer SoCs

spi: dt-bindings: sun6i: Allow Dual SPI and Quad SPI for newer SoCs

Support for Dual SPI and Quad SPI was added to the Linux driver in
commit 0605d9fb411f ("spi: sun6i: add quirk for dual and quad SPI modes
support") and commit 25453d797d7a ("spi: sun6i: add dual and quad SPI
modes support for R329/D1/R528/T113s").

However the binding was never updated to allow these modes. Allow them
by adding 2 and 4 to the allowed bus widths for the newer variants.

While at it, also add 0 to the allowed bus widths. This signals that
RX or TX is not available, i.e. the MISO or MOSI pin is disconnected.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Chen-Yu Tsai <wens@kernel.org>
Link: https://patch.msgid.link/20260302153559.3199783-2-wens@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>