console: Use flush() before panic and reset

To make sure the panic and the reset messages will go out, console flush() should be used.
Sleep periods do not work in early u-boot phase when timer driver is not initialized yet.

Reference: https://lists.denx.de/pipermail/u-boot/2023-March/512233.html

Signed-off-by: Tony Dinh <mibodhi@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>

arch/arm/lib/reset.c

@@ -25,6 +25,7 @@
 #include <cpu_func.h>
 #include <irq_func.h>
 #include <linux/delay.h>
+#include <stdio.h>
 
 __weak void reset_misc(void)
 {
@@ -33,8 +34,7 @@ __weak void reset_misc(void)
 int do_reset(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 {
 	puts ("resetting ...\n");
-
-	mdelay(50);				/* wait 50 ms */
+	flush();
 
 	disable_interrupts();