"pdev" is much more often used to point a platform_device, so this
will help the driver code look consistent across the kernel.

While we are here, fix "line over 80 characters" coding style
violations.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>