iwlwifi: remove IWL_*_UCODE_API_OK

_UCODE_API_OK was a intermediate version between MIN and
MAX. If a user had a firmware below _OK but above _MIN, the
driver would work but the user would get a warning in the
kernel log telling him to update his firmware.
This is not needed since most users won't look for these
messages in the kernel log if their wifi is working.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>