soc: wch: add the CH32V00x series

Compared to the CH32V003, the CH32V00x series is an evolution that
uses a different microarchitecture (V2C instead of V2A) and different
pinctrl mappings.

Fork the current qingke_v2a and use the new proposed naming convention.

Signed-off-by: Michael Hope <michaelh@juju.nz>