Bad page threshold value should be valid in the range between
-1 and max records length of eeprom. It could determine when
saved bad pages exceed threshold value, and proceed corresponding
actions.

v2: When using the default typical value, it should be min
value between typical value and eeprom max records length.

v3: drop the case of setting bad_page_cnt_threshold to be
    0xFFFFFFFF, as it confuses user.
Signed-off-by: Guchun Chen <guchun.chen@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>