boards: arm: nrf5340_dk_nrf5340: rename target to nrf5340pdk_nrf5340

We rename the nRF53 Dev Kit board target (nrf5340_dk_nrf5340)
to nrf5340pdk_nrf5340. We update all associated references
in the supportive documentation and all nRF5340-related
cofigurations and overlay files in the samples and tests
in the tree.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
26 files changed