arm64: dts: meson: odroid-c2: add missing mmc modes

Add sdcard uhs modes up to DDR50 and push eMMC up to 200Mhz
With the new tuning method, these modes appear to be stable

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>