arm: dts: mt7622: force high-speed mode for uart

The input clock for uart is too slow (25MHz) which introduces frequent data
error on both receiving and transmitting even if the baudrate is 115200.

Using high-speed can significantly solve this issue.

Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Daniel Golle <daniel@makrotopia.org>
1 file changed