Revert "crypto: montage: tsse_vuart: drop unused vuart_wait_for_xmitr()"

This reverts commit 355d339.

Author: MingcongBai

drivers/crypto/montage/tsse/tsse_vuart.c

@@ -74,6 +74,24 @@ static void vuart_serial_out(struct uart_port *port, int offset, int value)
 	writel(value, port->membase + offset);
 }
 
+static void vuart_wait_for_xmitr(struct uart_port *port)
+{
+	unsigned int status, tmout = 10000;
+
+	for (;;) {
+		status = vuart_serial_in(port, VUART_FSR);
+		if (FIELD_GET(VUART_FSR_TXFIFOE, status))
+			break;
+		if (--tmout == 0) {
+			pr_err("%s:timeout(10ms), TX is not empty.\n",
+			       __func__);
+			break;
+		}
+		udelay(1);
+		touch_nmi_watchdog();
+	}
+}
+
 static unsigned int vuart_tx_empty(struct uart_port *port)
 {
 	unsigned long flags;