cmd/fdt: Make fdt get value endian-safe for single-cell properties

On a Raspberry Pi 2 disagreements on cell endianness can be observed:

  U-Boot> fdt print /soc/gpio@7e200000 phandle
  phandle = <0x0000000d>
  U-Boot> fdt get value myvar /soc/gpio@7e200000 phandle; printenv myvar
  myvar=0x0D000000

Fix this by always treating the pointer as BE and converting it in
fdt_value_setenv(), like its counterpart fdt_parse_prop() already does.

Consistently use fdt32_t, fdt32_to_cpu() and cpu_to_fdt32().

Fixes: bc80295 ("fdt: Add get commands to fdt")
Cc: Joe Hershberger <joe.hershberger@ni.com>
Cc: Gerald Van Baren <gvb@unssw.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Acked-by: Simon Glass <sjg@chromium.org>

cmd/fdt.c

@@ -58,7 +58,7 @@ static int fdt_value_setenv(const void *nodep, int len, const char *var)
 	else if (len == 4) {
 		char buf[11];
 
-		sprintf(buf, "0x%08X", *(uint32_t *)nodep);
+		sprintf(buf, "0x%08X", fdt32_to_cpu(*(fdt32_t *)nodep));
 		setenv(var, buf);
 	} else if (len%4 == 0 && len <= 20) {
 		/* Needed to print things like sha1 hashes. */
@@ -768,7 +768,7 @@ static int fdt_parse_prop(char * const *newval, int count, char *data, int *len)
 
 			cp = newp;
 			tmp = simple_strtoul(cp, &newp, 0);
-			*(__be32 *)data = __cpu_to_be32(tmp);
+			*(fdt32_t *)data = cpu_to_fdt32(tmp);
 			data  += 4;
 			*len += 4;