board: tbs2910: fix HDMI pre-console buffer

HDMI output must be enabled very early to also enable the pre-console buffer
Signed-off-by: NSoeren Moch <smoch@web.de>
Reviewed-by: NStefano Babic <sbabic@denx.de>

include/configs/tbs2910.h

@@ -185,7 +185,9 @@
 			"setenv stderr serial;\0" \
 	"set_con_hdmi=setenv stdout serial,vga; " \
 			"setenv stderr serial,vga;\0" \
-	"stdin=serial,usbkbd;\0"
+	"stderr=serial,vga;\0" \
+	"stdin=serial,usbkbd;\0" \
+	"stdout=serial,vga;\0"
 
 #define CONFIG_BOOTCOMMAND \
 	"mmc rescan; " \