mmc: tmio: add flag to reduce delay after changing clock status

The docs for RCar Gen2 & 3 I have access to, mention delays of 5ms after
stop and 1ms after start. Make it possible to apply these values.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/include/linux/mfd/tmio.h b/include/linux/mfd/tmio.h
index 24b86d5..05d58ee 100644
--- a/include/linux/mfd/tmio.h
+++ b/include/linux/mfd/tmio.h
@@ -65,6 +65,10 @@
  * Some controllers can support SDIO IRQ signalling.
  */
 #define TMIO_MMC_SDIO_IRQ		(1 << 2)
+
+/* Some controllers don't need to wait 10ms for clock changes */
+#define TMIO_MMC_FAST_CLK_CHG		(1 << 3)
+
 /*
  * Some controllers require waiting for the SD bus to become
  * idle before writing to some registers.