arm64: dts: meson: improve gxm-khadas-vim2 wifi

Improve gxm-khadas-vim2 wifi performance
* change freq from 60Mhz to 100Mhz
* add cap-sd-highspeed param

100Mhz works well same as in meson-khadas-vim3.dtsi

Signed-off-by: Artem Lapkin <art@khadas.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://lore.kernel.org/r/20210622044334.769791-2-art@khadas.com