ARM: sa11x0: neponset: provide function to manipulate NCR_0

Rather than having direct register accesses to NCR_0 scattered amongst
the code, provide a function instead.  This contains the necessary
race protection for this platform, ensuring that updates to this
register are safe.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/net/ethernet/smsc/smc91x.c

@@ -2281,7 +2281,7 @@ static int __devinit smc_drv_probe(struct platform_device *pdev)
 	if (ret)
 		goto out_release_io;
 #if defined(CONFIG_SA1100_ASSABET)
-	NCR_0 |= NCR_ENET_OSC_EN;
+	neponset_ncr_set(NCR_ENET_OSC_EN);
 #endif
 	platform_set_drvdata(pdev, ndev);
 	ret = smc_enable_device(pdev);