mmc: sd: Macro name cleanup for high speed dtr

Add new macros for the high speed 50MHz case, rather than having
a confusing reuse of the value for UHS SDR50, which is 100MHz.

Reported-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index f2a05ea..f54392c 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -307,8 +307,8 @@
 		goto out;
 	}
 
-	if (status[13] & UHS_SDR50_BUS_SPEED)
-		card->sw_caps.hs_max_dtr = 50000000;
+	if (status[13] & SD_MODE_HIGH_SPEED)
+		card->sw_caps.hs_max_dtr = HIGH_SPEED_MAX_DTR;
 
 	if (card->scr.sda_spec3) {
 		card->sw_caps.sd3_bus_mode = status[13];