arm: dts: MediaTek: fix clock order for timer0 node of mt7629.dtsi

The timer0 node has its two clocks written in reversed order. The timer0
is used as the tick timer which causes a problem that the time a delay
function used is 4 times longer.

This patch reverses these two clocks to solve this issue.

Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>