plo: reading elf to struct ignores alignment

[anglov]

Data in plo is serialized directly to Elf structs, eg. in https://github.com/phoenix-rtos/plo/blob/cd80102775f353e995977aa3219657c4cfad4a3f/cmds/kernel.c#L61

Those structures is packed in kernel (https://github.com/phoenix-rtos/phoenix-rtos-kernel/blob/f69704d2fefcd675d62e3bfdc266f60733684d51/proc/elf.h#L61) but not in plo, where pragma nor packed is not used.