ARM: dts: kirkwood: gpio pin fixes for linkstation ls-wvl/vl

ARM: dts: kirkwood: gpio pin fixes for linkstation ls-wvl/vl

For kirkwood, gpio pins starts from 32 are in the 2nd bank, so it should be
converted to "gpio1 <pin minus 32>" in dts file.
e.g. gpio 40 should be "gpio1 8"

The pin/bank issue was found when discussing Debian Bug #810894
  [https://bugs.debian.org/810894#47]

Fixes: c43379e150aa ("ARM: dts: add buffalo linkstation ls-wvl/vl")
Reported-by: Arnaud Patard (Rtp) <arnaud.patard@rtp-net.org>
Signed-off-by: Roger Shimizu <rogershimizu@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>