rockchip: px30: sync serial flash controller bindings with mainline

The devicetree submitted and approved for the mainline linux kernel is
slightly different than the one present here. This syncs both
devicetrees (for the Rockchip SFC node at least) present on the PX30
and the Odroid Go Advance. Changes include renaming the flash node,
reordering the values in the SFC node for the rk3326-odroid-go2,
changing the name of the cs pinctrl node to cs0, and updating the
u-boot specific tree to utilize the new flash node value.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>