wl1251: fix module names

The wl1251 move accidently renamed wl1251_sdio and wl1251_spi
modules to just sdio and spi. Restore proper module names.

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