sfc: Use kernel I2C system and i2c-algo-bit driver

Remove our own implementation of I2C bit-banging.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/net/sfc/boards.h b/drivers/net/sfc/boards.h
index 695764d..e5e8443 100644
--- a/drivers/net/sfc/boards.h
+++ b/drivers/net/sfc/boards.h
@@ -20,8 +20,7 @@
 };
 
 extern int efx_set_board_info(struct efx_nic *efx, u16 revision_info);
-extern int sfe4001_poweron(struct efx_nic *efx);
-extern void sfe4001_poweroff(struct efx_nic *efx);
+extern int sfe4001_init(struct efx_nic *efx);
 /* Are we putting the PHY into flash config mode */
 extern unsigned int sfe4001_phy_flash_cfg;