ARM: dts: rockchip: fix the MiQi board's LED definition

ARM: dts: rockchip: fix the MiQi board's LED definition

The MiQi board's green LED doesn't work at all with the mainline kernel.
There are multiple reasons to this. First, the gpio number is wrong, it
is declared on gpio220 (chip 7 pin 4) instead of gpio218 (chip 7 pin 2).
Second, a pinctrl is referenced, also declared with the same wrong value
while it is not unused. Third, the GPIO polarity was wrong (active low
instead of active high) with the default value set to "default-on",
resulting in the LED being turned off even when the GPIO is correct.

This patch fixes all these inconsistencies at once since these they are
related to each other, and also restores the "timer" trigger which is
the same as the one used by the kernels shipped with the board.

It's important to note that during the port to mainline, the led's label
was changed from "System" to "miqi:green:user", so scripts making use of
the name will still not work until they're fixed.

Fixes: b1a76f75d76e ("ARM: dts: rockchip: add MiQi board from mqmaker")
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>