spi: allow attaching device properties to SPI board info

Generic device properties support statically defined property sets. For
them to be usable, we need to attach these property sets before devices
are registered and probed. Allowing to attach property list to
spi_board_info structure will allow non-ACPI non-DT boards switch to using
generic properties and get rid of custom platform data.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>