This externalizes and exports the symbol of_find_spi_controller_by_node() from the SPI core akin to how of_find_i2c_adapter_by_node() is already available. As we will need this also for non-dynamic OF setups, we move it under a CONFIG_OF check.
Would a change description be more desirable with a corresponding imperative wording?
See also: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Docu...
Regards, Markus