[SYS] Add save option to discovery and ohdiscovery key and remove discovery for Arduino boards (#1696)

Enabling to keep discovery off if required

Remove Mqtt discovery for Arduino UNO and ATMEGA

environments.ini

@@ -1397,6 +1397,7 @@ build_flags =
   '-DZmqttDiscovery="HADiscovery"'
   '-DsimplePublishing=true'
   '-DGateway_Name="OMG_ATMEGA_ALL"'
+  '-UZmqttDiscovery="HADiscovery"'
 
 [env:uno-rf]
 platform = ${com.atmelavr_platform}
@@ -1406,6 +1407,7 @@ lib_deps =
   ${libraries.rc-switch}
 build_flags =
   ${com-arduino-low-memory.build_flags}
+  '-UZmqttDiscovery="HADiscovery"'
   '-DZgatewayRF="RF"'
   '-DGateway_Name="OMG_1_RF"'
   '-DDISABLE_LOGGING'
@@ -1421,6 +1423,7 @@ build_flags =
   ${com-arduino-low-memory.build_flags}
   '-DGateway_Name="OMG_1_FL"'
   '-DZactuatorFASTLED="FASTLED"'
+  '-UZmqttDiscovery="HADiscovery"'
 custom_description = FastLed control
 
 [env:esp32dev-ble-datatest]