mmc: Define timing macro's

Define timing macro's for all the available speeds of mmc. This is
done similar to linux. Replace speed macro's used with these new timing
macro's wherever applicable.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
diff --git a/include/mmc.h b/include/mmc.h
index ac7b54f..1d377e0 100644
--- a/include/mmc.h
+++ b/include/mmc.h
@@ -360,6 +360,19 @@
 #define MMC_NUM_BOOT_PARTITION	2
 #define MMC_PART_RPMB           3       /* RPMB partition number */
 
+/* timing specification used */
+#define MMC_TIMING_LEGACY	0
+#define MMC_TIMING_MMC_HS	1
+#define MMC_TIMING_SD_HS	2
+#define MMC_TIMING_UHS_SDR12	3
+#define MMC_TIMING_UHS_SDR25	4
+#define MMC_TIMING_UHS_SDR50	5
+#define MMC_TIMING_UHS_SDR104	6
+#define MMC_TIMING_UHS_DDR50	7
+#define MMC_TIMING_MMC_DDR52	8
+#define MMC_TIMING_MMC_HS200	9
+#define MMC_TIMING_MMC_HS400	10
+
 /* Driver model support */
 
 /**