mmc: sdhci-esdhc-imx: do not touch other bit when config DTOCV

Now, when call esdhc_set_timeout() to set the data timeout counter value,
IPP_RST_N(bit 23) is wrongly affected. This patch add a mask to avoid this.
Signed-off-by: NHaibo Chen <haibo.chen@nxp.com>
Acked-by: NDong Aisheng <aisheng.dong@nxp.com>
Acked-by: NAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: NUlf Hansson <ulf.hansson@linaro.org>

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

@@ -31,6 +31,7 @@
 #include "sdhci-pltfm.h"
 #include "sdhci-esdhc.h"
 
+#define ESDHC_SYS_CTRL_DTOCV_MASK	0x0f
 #define	ESDHC_CTRL_D3CD			0x08
 #define ESDHC_BURST_LEN_EN_INCR		(1 << 27)
 /* VENDOR SPEC register */
@@ -937,7 +938,8 @@ static void esdhc_set_timeout(struct sdhci_host *host, struct mmc_command *cmd)
 	struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
 
 	/* use maximum timeout counter */
-	sdhci_writeb(host, esdhc_is_usdhc(imx_data) ? 0xF : 0xE,
+	esdhc_clrset_le(host, ESDHC_SYS_CTRL_DTOCV_MASK,
+			esdhc_is_usdhc(imx_data) ? 0xF : 0xE,
 			SDHCI_TIMEOUT_CONTROL);
 }