dm: device: Allow using uclass_find_device_by_seq() without OF_CONTROL

dm: device: Allow using uclass_find_device_by_seq() without OF_CONTROL

If OF_CONTROL is not enabled and DM_SEQ_ALIAS is enabled, we must
assign an alias (requested sequence number) to devices that belongs to a
class with the DM_UC_FLAG_SEQ_ALIAS flag. Otherwise
uclass_find_device_by_seq() cannot be used to get/probe a device. In
particular i2c_get_chip_for_busnum() cannot be used.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>