The emmc on px5-evb can support hs200, so let's add mmc-hs200-1_8v.
And in order to speed up the boot time, we could add no-sdio and
no-sd to simplify the initialization.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>