mmc: am654_sdhci: Use MMC_MODES_END value instead of hardcoded value

The hardcoded array size leads to array overflows with changes in
speed modes enum in mmc core. Use MMC_MODES_END for otap_del_sel
array declaration to fix this.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
diff --git a/drivers/mmc/am654_sdhci.c b/drivers/mmc/am654_sdhci.c
index cbc531d..82abf48 100644
--- a/drivers/mmc/am654_sdhci.c
+++ b/drivers/mmc/am654_sdhci.c
@@ -75,7 +75,7 @@
 	struct mmc mmc;
 	struct regmap *base;
 	bool non_removable;
-	u32 otap_del_sel[11];
+	u32 otap_del_sel[MMC_MODES_END];
 	u32 trm_icp;
 	u32 drv_strength;
 	u32 strb_sel;