native simulator: Get latest from upstream

Align with native_simulator's upstream main
64b8be6311a61df2c63987813e8058560c8dc49c

Which includes:
 * 64b8be6 Make: Give option to add extra localization parameters
 * 05bc3ce Generalize code for N CPUs/MCUs
 * 489069b Makefile: Generalize for N embedded images
 * a4c817e runner->embedded trampolines: Improve definitions
 * 8d8dd29 nsi_utils: Provide debracket macro
 * 6b4956e Add optional embedded test hook definition

Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>