airoha: spi: remove snfi driver dirty hack

airoha: spi: remove snfi driver dirty hack

This patch series removes dirty hack that reads flash page settings from
SNFI registers during driver startup.

Before these patches the airoha spi snfi driver needs to know spinand
flash page size. The driver can't get it from spinand subsystem, so the
following approach was implemented:
 * bootloader know the flash page size (and some other parameters)
 * to operate properly the bootloader writes flash page size (and some
   other parameters) to SNFI registers
 * bootloader starts linux
 * after linux start SNFI registers keeps the values stored by bootloader
 * linux snfi driver reads flash parameters from SNFI registers.

This works, but we can do better. It has been proven that flash page size
is actually unnecessary. We can get all required data from dirmap requests.

This patch series drops the hack and do things properly.

Signed-off-by: Mikhail Kshevetskiy <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/20295
Signed-off-by: Robert Marko <[email protected]>