bootm: Set working fdt address as part of the bootm flow

Set the fdt working address so "fdt FOO" commands can be used as part
of the bootm flow.  Also set an the environment variable "fdtaddr"
with the value.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/common/cmd_fdt.c b/common/cmd_fdt.c
index 94bca46..8bc900a 100644
--- a/common/cmd_fdt.c
+++ b/common/cmd_fdt.c
@@ -50,6 +50,16 @@
  */
 struct fdt_header *working_fdt;
 
+void set_working_fdt_addr(void *addr)
+{
+	char buf[17];
+
+	working_fdt = addr;
+
+	sprintf(buf, "%lx", (unsigned long)addr);
+	setenv("fdtaddr", buf);
+}
+
 /*
  * Flattened Device Tree command, see the help for parameter definitions.
  */
@@ -64,6 +74,7 @@
 	 * Set the address of the fdt
 	 ********************************************************************/
 	if (argv[1][0] == 'a') {
+		unsigned long addr;
 		/*
 		 * Set the address [and length] of the fdt.
 		 */
@@ -75,7 +86,8 @@
 			return 0;
 		}
 
-		working_fdt = (struct fdt_header *)simple_strtoul(argv[2], NULL, 16);
+		addr = simple_strtoul(argv[2], NULL, 16);
+		set_working_fdt_addr((void *)addr);
 
 		if (!fdt_valid()) {
 			return 1;