Fix remaining initial porting guide's issues
Fix remaining initial porting guide's issues

runtimeco/mcuboot,utzig/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot,tamban01/mcuboot,runtimeco/mcuboot,utzig/mcuboot,utzig/mcuboot,ATmobica/mcuboot,tamban01/mcuboot,ATmobica/mcuboot,runtimeco/mcuboot,tamban01/mcuboot,utzig/mcuboot,tamban01/mcuboot,ATmobica/mcuboot,tamban01/mcuboot,ATmobica/mcuboot,utzig/mcuboot,runtimeco/mcuboot