driver core: Rename declaration parameter name for API device_find_child() cluster

driver core: Rename declaration parameter name for API device_find_child() cluster

For APIs:
device_find_child()
device_for_each_child()
device_for_each_child_reverse()

Their declaration has parameter name 'dev', but their defination
changes the name to 'parent'.

Rename declaration name to defination 'parent' to make both have
the same name.

Reviewed-by: Fan Ni <fan.ni@samsung.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/20250105-class_fix-v6-4-3a2f1768d4d4@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>