spi: dw: Add update_cr0() callback to update CTRLR0

This patch adds update_cr0() callback, in struct dw_spi.

Existing code that configure register CTRLR0 is moved into a new
function, dw_spi_update_cr0(), and this will be the default.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200505130618.554-3-wan.ahmad.zainie.wan.mohamad@intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index 0d86c37..9cc010e 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -318,5 +318,9 @@ int dw_spi_mid_init(struct dw_spi *dws)
 	dws->dma_rx = &mid_dma_rx;
 	dws->dma_ops = &mid_dma_ops;
 #endif
+
+	/* Register hook to configure CTRLR0 */
+	dws->update_cr0 = dw_spi_update_cr0;
+
 	return 0;
 }