wl1251: don't require NVS data when EEPROM is used

If EEPROM is used, NVS data is now loaded but ignored.
Stop loading it to avoid need of dummy NVS file for modules with EEPROM.

Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>
Acked-by: Kalle Valo <kvalo@adurom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>