lcd: Fix compile warning in 64bit mode

When compiling the code for 64bit, the lcd code emits warnings because it
tries to cast pointers to 32bit values. Fix it by casting them to longs
instead, actually properly aligning with the function prototype.

Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/common/lcd.c b/common/lcd.c
index 51705ad..783626e 100644
--- a/common/lcd.c
+++ b/common/lcd.c
@@ -66,8 +66,8 @@
 	int line_length;
 
 	if (lcd_flush_dcache)
-		flush_dcache_range((u32)lcd_base,
-			(u32)(lcd_base + lcd_get_size(&line_length)));
+		flush_dcache_range((ulong)lcd_base,
+			(ulong)(lcd_base + lcd_get_size(&line_length)));
 #endif
 }