ipq40xx: fix invalid GPIO numbers since kernel 6.6

ipq40xx: fix invalid GPIO numbers since kernel 6.6

The bump to kernel 6.6 increased the GPIO base from
412 to 512 on this target.

We need to compensate for that in the GPIO numbers being passed
to uci to fix following kernel report:

[   24.176183] export_store: invalid GPIO 423

Tested on a Wallys DR40x9 board.

Please note that:

Boards "rtl30vw" and "wpj428" are not being altered here.
They define GPIO numbers which are even below the previous
base of 412 which looks wrong.
Actual testing on these boards should be conducted to validate
and optionally fix GPIO numbering.

Suggested-by: Robert Marko <robimarko@gmail.com>
Signed-off-by: Koen Vandeputte <koen.vandeputte@citymesh.com>