arm64: dts: qcom: ipq5424: correct the TF-A reserved memory to 512K

arm64: dts: qcom: ipq5424: correct the TF-A reserved memory to 512K

Correct the reserved memory size for TF-A to 512K, as it was mistakenly
marked as 500K. Update the reserved memory node accordingly.

Fixes: 8517204c982b ("arm64: dts: qcom: ipq5424: Add reserved memory for TF-A")
Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20251014-tfa-reserved-mem-v1-1-48c82033c8a7@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>