mtd: spi-nor: add support for Macronix Octal flash

Add manufacturer ID 0xc2 at the end of ID table to allow manufacturer
fixups to be applied for any Macronix flash. This spares us of adding
new flash entries for flashes that can be initialized solely based on
the SFDP data, but still need the manufacturer hooks to set parameters
that can't be discovered at SFDP parsing time.

The ID is added in order to set the octal DTR methods. SFDP defines a
"Command Sequences to Change to Octal DDR (8D-8D-8D) Mode" which can
enable the octal DTR mode. Until that is parsed and used, use the
local defined method.

Suggested-by: Michael Walle <mwalle@kernel.org>
Signed-off-by: JaimeLiao <jaimeliao@mxic.com.tw>
Signed-off-by: AlvinZhou <alvinzhou@mxic.com.tw>
Link: https://lore.kernel.org/r/20240926141956.2386374-7-alvinzhou.tw@gmail.com


[ta: update commit message and comment in the code]
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>