default or selected kernelversion does not have config value CONFIG_MTD_NAND_OMAP_BCH8.
Result is shown for kernelversion 6.2.5

8 bits / 512 bytes (recommended)

configname: CONFIG_MTD_NAND_OMAP_BCH8

BCH error correction capability
└─>8 bits / 512 bytes (recommended)
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Support correcting up to 8 bitflips per 512-byte block.
This will use 13 bytes of spare area per 512 bytes of page data.
This is the recommended mode, as 4-bit mode does not work
on some OMAP3 revisions, due to a hardware bug.