rtc: ds1305: use to_spi_device and kobj_to_dev

For better readability, use to_spi_device() and kobj_to_dev() instead
of container_of().

Signed-off-by: Geliang Tang <geliangtang@163.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
1 file changed