[FL-942] remove 3s delays in reset, dfu and poweroff CLI commands (#362)

applications/power/power.c

@@ -144,21 +144,15 @@ void power_free(Power* power) {
 }
 
 void power_cli_poweroff(string_t args, void* context) {
-    printf("Poweroff in 3 seconds");
-    osDelay(3000);
     api_hal_power_off();
 }
 
 void power_cli_reset(string_t args, void* context) {
-    printf("NVIC System Reset in 3 seconds");
-    osDelay(3000);
     NVIC_SystemReset();
 }
 
 void power_cli_dfu(string_t args, void* context) {
-    printf("NVIC System Reset to DFU mode in 3 seconds");
     api_hal_boot_set_mode(ApiHalBootModeDFU);
-    osDelay(3000);
     NVIC_SystemReset();
 }