mmc: tegra: properly disable card clock

commit 3491b690 upstream.

The new code to do the clock rate setting externally to the SDMMC
module has a shortcut to not propagate changes with a 0 rate to
the CAR by simply bailing out. This breaks proper cutting of the
card clock. Fix it by directly calling the correct sdhci function.

Fixes: a8e326a9 "mmc: tegra: implement module external clock change"
Signed-off-by: Lucas Stach <dev@lynxeye.de>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/mmc/host/sdhci-tegra.c

@@ -194,7 +194,7 @@ static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
 	unsigned long host_clk;
 
 	if (!clock)
-		return;
+		return sdhci_set_clock(host, clock);
 
 	host_clk = tegra_host->ddr_signaling ? clock * 2 : clock;
 	clk_set_rate(pltfm_host->clk, host_clk);