boards: rp2040: fix missing ranges for RP2040-based boards Add the `ranges` property to the flash node on RP2040-based boards to correctly specify the base address and size for child nodes. This aligns the board device trees with expected Zephyr DT conventions and ensures proper address translation for flash partitions and other child nodes. Signed-off-by: David Schneider <schneidav81@gmail.com>