Add 64-bit data support for memory commands

Add 64-bit data for memory commands, such as md, mw, mm, cmp. The new
size ".q " is introduced.

For 64-bit architecture, 64-bit data is enabled by default, by detecting
compiler __LP64__. It is optional for other architectures.

Signed-off-by: York Sun <yorksun@freescale.com>

include/common.h

@@ -96,6 +96,10 @@ typedef volatile unsigned char	vu_char;
 #include <flash.h>
 #include <image.h>
 
+#ifdef __LP64__
+#define CONFIG_SYS_SUPPORT_64BIT_DATA
+#endif
+
 #ifdef DEBUG
 #define _DEBUG	1
 #else