riscv: dts: starfive: jh7110: add DMC memory controller

riscv: dts: starfive: jh7110: add DMC memory controller

Add JH7110 SoC DDR external memory controller.

Signed-off-by: E Shattow <e@freeshell.de>
Reviewed-by: Hal Feng <hal.feng@starfivetech.com>
Reviewed-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>