spi: Create helper API to lookup ACPI info for spi device

This can then be used to find a spi resource inside an
ACPI node, and allocate a spi device.

Signed-off-by: Stefan Binding <sbinding@opensource.cirrus.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220121172431.6876-3-sbinding@opensource.cirrus.com


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