dm: core: Mirror the chosen node parse logic in the livetree scanning

dm: core: Mirror the chosen node parse logic in the livetree scanning

Commit f2006808f099: ("dm: core: parse chosen node") added a logic
to parse the chosen node during dm_scan_fdt_node(), but unfortunately
it missed adding the same logic in dm_scan_fdt_live(). This mirrors
the logic in the livetree version.

The weird thing is that commit f2006808f099 did update the test case
to test such logic, but even if I reset to that commit, the test case
still fails, and I have no idea how it could pass.

With this fix, the following 2 test cases now pass:

Test: dm_test_bus_children: bus.c
test/dm/bus.c:112, dm_test_bus_children(): num_devices ==
list_count_items(&uc->dev_head): Expected 7, got 6

Test: dm_test_fdt: test-fdt.c
test/dm/test-fdt.c:184, dm_test_fdt(): num_devices ==
list_count_items(&uc->dev_head): Expected 7, got 6

Fixes: f2006808f099 ("dm: core: parse chosen node")
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>