ARM: dts: wpcm450: Add global control registers (GCR) node

ARM: dts: wpcm450: Add global control registers (GCR) node

The Global Control Registers (GCR) are a block of registers in Nuvoton
SoCs that expose misc functionality such as chip model and version
information or pinmux settings.

This patch adds a GCR node to nuvoton-wpcm450.dtsi in preparation for
enabling pinctrl on this SoC.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20220129115228.2257310-4-j.neuschaefer@gmx.net
Signed-off-by: Joel Stanley <joel@jms.id.au>