mtd: spinand: Create an array of operation templates

mtd: spinand: Create an array of operation templates

Currently, the SPI NAND core implementation directly calls macros to get
the various operations in shape. These macros are specific to the bus
interface, currently only supporting the single SDR interface (any
command following the 1S-XX-XX pattern).

Introducing support for other bus interfaces (such as octal DTR) would
mean that every user of these macros should become aware of the current
bus interface and act accordingly, picking up and adapting to the
current configuration. This would add quite a bit of boilerplate, be
repetitive as well as error prone in case we miss one occurrence.

Instead, let's create a table with all SPI NAND memory operations that
are currently supported. We initialize them with the same single SDR _OP
macros as before. This opens the possibility for users of the individual
macros to make use of these templates instead. This way, when we will add
another bus interface, we can just switch to another set of templates
and all users will magically fill in their spi_mem_op structures with
the correct ops.

The existing read, write and update cache variants are also moved in
this template array, which is barely noticeable by callers as we also
add a structure member pointing to it.

Reviewed-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>