Rework board_boot_image() to use a fixed handoff layout instead of heap\nallocation in the final chain-boot path.\n\n- validate load-header entry and segment placement against reserved regions\n- reserve top DRAM area for handoff args + new stack\n- reserve top IRAM area for a copied boot stub\n- map segments via bootloader_mmap/munmap and copy RTC segments before handoff\n- jump through copied IRAM stub to perform IRAM/DRAM final copy and branch\n to the new entry point
Signed-off-by: aviralgarg05 <gargaviral99@gmail.com>