mmc: renesas_sdhi: Add manual correction

This patch adds a manual correction mechanism for SDHI. Currently, SDHI
uses automatic TAP position correction. However, TAP position can also
be corrected manually via correction error status flags.

Signed-off-by: Takeshi Saito <takeshi.saito.xv@renesas.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20191217114034.13290-3-wsa+renesas@sang-engineering.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/renesas_sdhi.h

@@ -57,6 +57,7 @@ struct renesas_sdhi {
 	void __iomem *scc_ctl;
 	u32 scc_tappos;
 	u32 scc_tappos_hs400;
+	bool doing_tune;
 };
 
 #define host_to_priv(host) \