There are some specific pins (i.e. MMC/SD) need specific registers to
turn on/off the 10K & 50k(75K) resistors when pull up/down.

Therefore, this patch adds the custom prarmeters so that the user could
control it through device tree.
Signed-off-by: Ryder.Lee <ryder.lee@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>