mmc: uniphier-sd: Factor out register IO

This patch prepares the driver to support controller(s) with registers
at locations shifted by constant. Pull out the readl()/writel() from
the driver into separate functions, where the adjustment of the register
offset can be easily contained.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
1 file changed