ramips: add Sanlinking Technologies D240 pinmux quirk

ramips: add Sanlinking Technologies D240 pinmux quirk

The sd function of the nd_sd group configures two of the groups pins as
gpios. The pins are used as PCIe reset/power.

Due to the driver load order, the pins are configured way to late if
triggered by the sd-card driver.

To not introduce another kind of driver load order dependency and
configure the pins as early as possible, means during pinmux driver
load.

Signed-off-by: Mathias Kresin <dev@kresin.me>
(backported from 71ba834cf1a1c8fcbf345b7efa75de0dcba9db20)