arm64: dts: exynos7870-j6lte: reduce memory ranges to base amount

arm64: dts: exynos7870-j6lte: reduce memory ranges to base amount

The device is available in multiple variants with differing RAM
capacities. The memory range defined in the 0x80000000 bank exceeds the
address range of the memory controller, which eventually leads to ARM
SError crashes. Reduce the bank size to a value which is available to
all devices.

The bootloader must be responsible for identifying the RAM capacity and
editing the memory node accordingly.

Fixes: d6f3a7f91fdb ("arm64: dts: exynos: add initial devicetree support for exynos7870")
Cc: stable@vger.kernel.org # v6.16
Signed-off-by: Kaustabh Chakraborty <kauschluss@disroot.org>
Link: https://lore.kernel.org/r/20250626-exynos7870-dts-fixes-v1-3-349987874d9a@disroot.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>