mmc: sdhci: avoid double-delay while transitioning to 1.8V

The MMC core in mmc_set_signal_voltage() already provides for the delay
required to switch to 1.8V, so there is no need for drivers to perform
this wait themselves.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci.c

@@ -1768,9 +1768,6 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host,
 		ctrl |= SDHCI_CTRL_VDD_180;
 		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
 
-		/* Wait for 5ms */
-		usleep_range(5000, 5500);
-
 		/* 1.8V regulator output should be stable within 5 ms */
 		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
 		if (ctrl & SDHCI_CTRL_VDD_180)