wl1251: separate bus i/o code into io.c

In order to eventually support wl1251 spi and sdio interfaces, move
the register and memory transfer functions to a common file.  Also
rename wl1251_spi_mem_{read,write} to indicate its common usage.
We still use spi_read internally until SDIO interface is introduced
so nothing functional should change here.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/wl12xx/wl1251_ps.c b/drivers/net/wireless/wl12xx/wl1251_ps.c
index 68ff7f1..0581677 100644
--- a/drivers/net/wireless/wl12xx/wl1251_ps.c
+++ b/drivers/net/wireless/wl12xx/wl1251_ps.c
@@ -23,7 +23,8 @@
 
 #include "reg.h"
 #include "wl1251_ps.h"
-#include "wl1251_spi.h"
+#include "wl1251_cmd.h"
+#include "wl1251_io.h"
 
 #define WL1251_WAKEUP_TIMEOUT 2000