mmc: sdhci-esdhc-imx: add delay between tuning cycles

It's observed that i.MX uSDHC needed delay between tuning
cycles for HS200 successful tuning. This patch is to set 1ms
delay for that.
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-esdhc-imx.c

@@ -1390,6 +1390,8 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
 	if (err)
 		goto disable_ahb_clk;
 
+	host->tuning_delay = 1;
+
 	sdhci_esdhc_imx_hwinit(host);
 
 	err = sdhci_add_host(host);