hw/loongarch: Fix fdt memory node wrong 'reg'

hw/loongarch: Fix fdt memory node wrong 'reg'

The right fdt memory node like [1], not [2]

  [1]
        memory@0 {
                device_type = "memory";
                reg = <0x00 0x00 0x00 0x10000000>;
        };
  [2]
        memory@0 {
                device_type = "memory";
                reg = <0x02 0x00 0x02 0x10000000>;
        };

Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20240426091551.2397867-10-gaosong@loongson.cn>
(cherry picked from commit b11f9814526b833b3a052be2559457b1affad7f5)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>