mmc: core: Remove redundant code in mmc_set_signal_voltage()

The mmc_set_signal_voltage() function is used for SD/SDIO when switching to
1.8V for UHS mode. Therefore let's remove the redundant code dealing with
MMC_SIGNAL_VOLTAGE_330.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Tested-by: Jan Glauber <jglauber@cavium.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 8c45825..bb819d4 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1654,13 +1654,6 @@
 	u32 clock;
 
 	/*
-	 * Send CMD11 only if the request is to switch the card to
-	 * 1.8V signalling.
-	 */
-	if (signal_voltage == MMC_SIGNAL_VOLTAGE_330)
-		return __mmc_set_signal_voltage(host, signal_voltage);
-
-	/*
 	 * If we cannot switch voltages, return failure so the caller
 	 * can continue without UHS mode
 	 */