spi: dw: use managed resources

Migrate mmio code and core driver to managed resources to reduce boilerplate
error handling code. Also, handle clk_enable() failure while at it, and drop
unused dw_spi iolen field.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
index 5a5cd02..587643d 100644
--- a/drivers/spi/spi-dw.h
+++ b/drivers/spi/spi-dw.h
@@ -92,13 +92,11 @@
 struct dw_spi {
 	struct spi_master	*master;
 	struct spi_device	*cur_dev;
-	struct device		*parent_dev;
 	enum dw_ssi_type	type;
 	char			name[16];
 
 	void __iomem		*regs;
 	unsigned long		paddr;
-	u32			iolen;
 	int			irq;
 	u32			fifo_len;	/* depth of the FIFO buffer */
 	u32			max_freq;	/* max bus freq supported */
@@ -230,7 +228,7 @@
 	void (*cs_control)(u32 command);
 };
 
-extern int dw_spi_add_host(struct dw_spi *dws);
+extern int dw_spi_add_host(struct device *dev, struct dw_spi *dws);
 extern void dw_spi_remove_host(struct dw_spi *dws);
 extern int dw_spi_suspend_host(struct dw_spi *dws);
 extern int dw_spi_resume_host(struct dw_spi *dws);