rpi: always scroll by 10 lines

Scrolling the simple framebuffer is really slow in Raspberry Pi to the
point it delays the boot by a second or two and makes longer output
inconvenient to follow (printenv, md).

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>

include/configs/rpi-common.h

@@ -68,6 +68,7 @@
 #define CONFIG_FB_ADDR			0
 #define CONFIG_VIDEO_BCM2835
 #define CONFIG_SYS_WHITE_ON_BLACK
+#define CONFIG_CONSOLE_SCROLL_LINES	10
 
 /* SD/MMC configuration */
 #define CONFIG_GENERIC_MMC