Fix CFG_NO_FLASH compilation.

Many Atmel boards have no "real" (NOR) flash on board, and rely only
on DataFlash and NAND memories. This patch enables CFG_NO_FLASH to
be present in a board configuration file, while still enabling flash
commands like 'flinfo', 'protect', etc.

Signed-off-by: Stelian Pop <stelian@popies.net>
diff --git a/common/cmd_mem.c b/common/cmd_mem.c
index 4262e26..d6d7a5b 100644
--- a/common/cmd_mem.c
+++ b/common/cmd_mem.c
@@ -492,7 +492,11 @@
 	}
 
 	/* Check if we are copying from DataFlash to RAM */
-	if (addr_dataflash(addr) && !addr_dataflash(dest) && (addr2info(dest)==NULL) ){
+	if (addr_dataflash(addr) && !addr_dataflash(dest)
+#ifndef CFG_NO_FLASH
+				 && (addr2info(dest) == NULL)
+#endif
+	   ){
 		int rc;
 		rc = read_dataflash(addr, count * size, (char *) dest);
 		if (rc != 1) {