cmd_fdt: save fdtaddr in hex format

cmd_fdt: save fdtaddr in hex format

Commit 90fbee3e4051 ("cmd_fdt: Actually fix fdt command in sandbox")
changed the format(from hex address to unsigned long) in which "fdtaddr"
is saved . However do_fdt continues reads the "fdtaddr" assuming it to
be in hex format. This may lead to fdt being either loaded or attempted
to load at erroneous address generating fault if the address is out of
memory.

This patch changes back the format to hex while saving the "fdtaddr"
as it was done before.

Signed-off-by: Sudeep Holla <[email protected]>
Cc: Linus Walleij <[email protected]>
Cc: Tom Rini <[email protected]>
Cc: Simon Glass <[email protected]>
Cc: Hua Yanghao <[email protected]>
Cc: Heiko Schocher <[email protected]>
Acked-by: Linus Walleij <[email protected]>
Acked-by: Simon Glass <[email protected]>