arm64: dts: meson-g12-common: specify full DMC range

arm64: dts: meson-g12-common: specify full DMC range

According to S905X2 Datasheet - Revision 07:
DRAM Memory Controller (DMC) register area spans ff638000-ff63a000.

According to DeviceTree Specification - Release v0.4-rc1:
simple-bus nodes do not require reg property.

Fixes: 1499218c80c99a ("arm64: dts: move common G12A & G12B modes to meson-g12-common.dtsi")
Signed-off-by: Marc Gonzalez <mgonzalez@freebox.fr>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20230327120932.2158389-2-mgonzalez@freebox.fr
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>