drivers: pinctrl: add a driver for the CH32V00x series

The CH32V006 and others in the CH32V00x series are an evolution of the
CH32V003 and use different remap offsets for the various peripherals.

In the same way as the CH32V20x, fork the CH32V003 driver and add
CH32V00x support.

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