Apply the following changes to `nrf54h20dk` and `nrf9280pdk`:
* Convert `perm-*` properties to the newly introduced `nordic,access`,
both in board files and tests.
* Redefine shared regions to specify multiple access owners per node,
and ensure that each such region is reserved by one domain at a time.
`cpuapp_cpurad_ram0x_region` is only enabled by Radiocore, while
`cpuapp_cpucell_ram0x_region` is only enabled by Application core.
* Divide `shared_ram3x_region` so that each sub-region is owned by a
different domain. Their addresses must be rounded down to fit the
current UICR format.
Signed-off-by: Grzegorz Swiderski <grzegorz.swiderski@nordicsemi.no>
13b1cfa5ec