target: msm8974: Add target ununit function

Add target ununit function to perform target specific
cleanup before jumping to kernel.

Change-Id: I24087a73af1d70a56aa3fc4102facd841bd86a2f
diff --git a/target/msm8974/init.c b/target/msm8974/init.c
index daa98b7..97f4222 100644
--- a/target/msm8974/init.c
+++ b/target/msm8974/init.c
@@ -557,8 +557,13 @@
 	return 0;
 }
 
-void target_usb_stop(void)
+void target_uninit(void)
 {
+#if MMC_SDHCI_SUPPORT
+	mmc_put_card_to_sleep(dev);
+#else
+	mmc_put_card_to_sleep();
+#endif
 #ifdef SSD_ENABLE
 	clock_ce_disable(SSD_CE_INSTANCE_1);
 #endif