tests: drivers: add flash_simulator driver

This commit adds a tests for flash simulator driver implementation
for qemu_x86 boards.

Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>
Signed-off-by: Kamil Piszczek <Kamil.Piszczek@nordicsemi.no>
5 files changed