removed pallet::getter usage from cumulus pallets (#3471)

Part of #3326 

@ggwpez @kianenigma @shawntabrizi

polkadot address: 12poSUQPtcF1HUPQGY3zZu2P8emuW9YnsPduA4XG3oCEfJVp

---------

Signed-off-by: Matteo Muraca <mmuraca247@gmail.com>

cumulus/parachains/pallets/parachain-info/src/lib.rs

@@ -54,7 +54,7 @@ pub mod pallet {
 	#[pallet::genesis_build]
 	impl<T: Config> BuildGenesisConfig for GenesisConfig<T> {
 		fn build(&self) {
-			<ParachainId<T>>::put(self.parachain_id);
+			ParachainId::<T>::put(self.parachain_id);
 		}
 	}
 
@@ -64,13 +64,18 @@ pub mod pallet {
 	}
 
 	#[pallet::storage]
-	#[pallet::getter(fn parachain_id)]
 	pub(super) type ParachainId<T: Config> =
 		StorageValue<_, ParaId, ValueQuery, DefaultForParachainId>;
 
 	impl<T: Config> Get<ParaId> for Pallet<T> {
 		fn get() -> ParaId {
-			Self::parachain_id()
+			ParachainId::<T>::get()
+		}
+	}
+
+	impl<T: Config> Pallet<T> {
+		pub fn parachain_id() -> ParaId {
+			ParachainId::<T>::get()
 		}
 	}
 }