This region is only required if certain fast peripherals make use of such
region for DMAing. It was now enabled on all builds, often resulting in:
```
[134/134] Linking C executable zephyr/zephyr.elf
Memory region Used Size Region Size %age Used
FLASH: 24372 B 248 KB 9.60%
RAM: 4448 B 256 KB 1.70%
DMA_RAM21: 0 GB 16 KB 0.00% <~~ Not used!
DMA_RAM3x_APP: 40 B 4 KB 0.98%
IDT_LIST: 0 GB 32 KB 0.00%
```
Signed-off-by: Gerard Marull-Paretas <gerard@teslabs.com>
Getting the required alignment size for memory region node
and device node needs to be handled by a separate macro.
Otherwise alignment of single byte is reported for any region.
Add a test that checks for this particular issue.
Signed-off-by: Nikodem Kastelik <nikodem.kastelik@nordicsemi.no>
After changing dmm to not apply data cache line alignment for all
regions test needs to be aligned.
Signed-off-by: Krzysztof Chruściński <krzysztof.chruscinski@nordicsemi.no>
