linux-phytec-ti

rtc-puv3: using module_platform_driver()

This patch converts the driver to use the module_platform_driver()
macro which makes the code smaller and a bit simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>