common/Kconfig: Change the default BOOTDELAY to 2

The value of 0 is fairly uncommon while 2 is one of the more common ones
so switch.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/common/Kconfig b/common/Kconfig
index 4d17b10..e691145 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -99,7 +99,7 @@
 
 config BOOTDELAY
 	int "delay in seconds before automatically booting"
-	default 0
+	default 2
 	help
 	  Delay before automatically running bootcmd;
 	  set to -1 to disable autoboot.