Video: fix compiler warnings in bus_vcxk

if a board uses the vcxk driver option CONFIG_SYS_VCXK_DOUBLEBUFFERD,
compilier shows warnings. This patch will fix it.
Signed-off-by: NJens Scharsig (BuS Elektronik) <esw@bus-elektronik.de>

drivers/video/bus_vcxk.c

@@ -153,7 +153,7 @@ int vcxk_init(unsigned long width, unsigned long height)
 #ifdef CONFIG_SYS_VCXK_DOUBLEBUFFERED
 	double_bws_word  = (u_short *)double_bws;
 	double_bws_long  = (u_long *)double_bws;
-	debug("%lx %lx %lx \n", double_bws, double_bws_word, double_bws_long);
+	debug("%px %px %px\n", double_bws, double_bws_word, double_bws_long);
 #endif
 	display_width  = width;
 	display_height = height;