boot: airoha: snfi: remove dirty hack required for both u-boot & linux

boot: airoha: snfi: remove dirty hack required for both u-boot & linux

This patch removes dirty hack used to:
 * operate with flash
 * pass flash page settings to linux driver via SNFI registers

It has been proven that spinand flash page size is actually unnecessary.
We can get all required data from dirmap requests. Thus this patch
series drops the hack and do things properly.

After this fix (and corresponding linux fix) the hack is not needed
anymore.

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
Link: https://github.com/openwrt/openwrt/pull/20295
Signed-off-by: Robert Marko <robimarko@gmail.com>