test: fdt: fix run_commandf() warnings

test: fdt: fix run_commandf() warnings

Fix warnings both for 32bit and 64bit architecture after adding
printf-like attribute format for run_commandf():
warning: format ‘%x’ expects argument of type ‘unsigned int’, but
  argument 2 has type ‘ulong {aka long unsigned int}’ [-Wformat=]
  ret = run_commandf("fdt addr -c %08x", addr);
                     ^
Signed-off-by: Evgeny Bachinin <EABachinin@sberdevices.ru>
Cc: Marek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
[trini: Fixup testcases added since patch was posted]
Signed-off-by: Tom Rini <trini@konsulko.com>