dt-bindings: spi: add reference file to YAML

In JH7110 SoC, the spi module needs to use "arm,primecell-periphid" to
override the h/w ID value to  correctly init "spi_dev", so add
"primecell.yaml" as the reference file for YAML.

Signed-off-by: William Qiu <william.qiu@starfivetech.com>
Link: https://lore.kernel.org/r/20230724101054.25268-2-william.qiu@starfivetech.com


Signed-off-by: Mark Brown <broonie@kernel.org>