Some controllers are exposing high-level interfaces to access various
kind of SPI memories. Unfortunately they do not fit in the current
spi_controller model and usually have drivers placed in
drivers/mtd/spi-nor which are only supporting SPI NORs and not SPI
memories in general.

This is an attempt at defining a SPI memory interface which works for
all kinds of SPI memories (NORs, NANDs, SRAMs).
Signed-off-by: NBoris Brezillon <boris.brezillon@bootlin.com>
Reviewed-by: NFrieder Schrempf <frieder.schrempf@exceet.de>
Tested-by: NFrieder Schrempf <frieder.schrempf@exceet.de>
Signed-off-by: NMark Brown <broonie@kernel.org>