scripts: mpu align for ro section of new memory region on non-XIP system

on non-XIP system, SRAM is the default region, and relocated .data
section and .bss section of SRAM shouldn't be inserted between
_image_rom_start and _image_rom_end, because the memory region between
_image_rom_start and _image_rom_end will construct the mpu ro region.
Also for the newly added memory region on non-XIP system, the
relocated .text secition and .rodata section should also be mpu aligned.

Fixes: #16090.

Signed-off-by: Wentong Wu <wentong.wu@intel.com>