Fix eMMC emergency reboot kernel will panic because NPE

Change-Id: I11459a3a6af0adae5d8fbfef2206198c36db534d
Reviewed-on: https://tp-biosrd-v02/gerrit/82823
Reviewed-by: Alex Cheng(鄭富元) <[email protected]>
Tested-by: Alex Cheng(鄭富元) <[email protected]>
(cherry picked from commit 976b702)
Reviewed-on: https://tp-biosrd-v02/gerrit/82824

Author: alex3788

drivers/mmc/host/dw_mmc.c

@@ -2669,7 +2669,7 @@ static void dw_mci_slot_of_parse(struct dw_mci_slot *slot)
 
 struct dw_mci *mSdhost;
 void setmmcEmergency() {
-	struct mmc_host *mmc = mSdhost->cur_slot->mmc;
+	struct mmc_host *mmc = mSdhost->slot[0]->mmc;
 	int ret;
 
 	mmc_power_off(mmc);