west_commands: nrfjprog: Add handling of data targeting the XIP region

When a hex file contains some data that needs to be programmed using
the QSPI peripheral (because it targets the XIP region), nrfjprog
needs to be provided with an option that specifies the QSPI erase
method to be used (otherwise, reprogramming will fail).
This commit adds the "--qspisectorerase" option when needed and it
also fixes the programming routine for nRF53, so that data for the
XIP region is not incorrectly interpreted as intended for the network
core.

Signed-off-by: Andrzej Głąbek <andrzej.glabek@nordicsemi.no>