mmc: sdhci-of-esdhc: temporary fixup for eMMC HS400 issue

Currently only LX2160A eSDHC supports eMMC HS400. According to
a large number of tests, eMMC HS400 failed to work at 150MHz,
and for a few boards failed to work at 175MHz. But eMMC HS400
worked fine on 200MHz. We hadn't found the root cause but
setting eSDHC_DLLCFG0[DLL_FREQ_SEL] = 0 using slow delay chain
seemed to resovle this issue. Let's use this as fixup for now.

Signed-off-by: Yangbo Lu <[e-mail]>
Signed-off-by: Ulf Hansson <[e-mail]>

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

···
 		esdhc_clock_enable(host, true);
 
 		temp = sdhci_readl(host, ESDHC_DLLCFG0);
-		temp |= ESDHC_DLL_ENABLE | ESDHC_DLL_FREQ_SEL;
+		temp |= ESDHC_DLL_ENABLE;
+		if (host->mmc->actual_clock == MMC_HS200_MAX_DTR)
+			temp |= ESDHC_DLL_FREQ_SEL;
 		sdhci_writel(host, temp, ESDHC_DLLCFG0);
 		temp = sdhci_readl(host, ESDHC_TBCTL);
 		sdhci_writel(host, temp | ESDHC_HS400_WNDW_ADJUST, ESDHC_TBCTL);