net/fm10k/base: clean up the logic

net/fm10k/base: clean up the logic

Clean up the logic in fm10k_tlv_attr_parse, we
should not reply on that FM10K_NOT_IMPLEMENTED is
greater than zero, as this can easily cause confusion.
The patch also correct a minor document error.

Signed-off-by: Qi Zhang <qi.z.zhang@intel.com>