fix c33 build warnings

src/kvstore/implementation/portentac33.cpp

@@ -18,6 +18,7 @@ bool PortentaC33KVStore::begin() {
 }
 
 bool PortentaC33KVStore::begin(bool reformat, mbed::KVStore* store) {
+    (void) reformat;
     // bd gets allocated if a kvstore is not provided as parameter here
     // if either one of bd or kvstore is different from NULL it means that the kvstore
     // had already been called begin on

src/kvstore/implementation/portentac33.h

@@ -32,6 +32,6 @@ class PortentaC33KVStore: public KVStoreInterface {
     typename KVStoreInterface::res_t getBytes(const key_t& key, uint8_t b[], size_t s) const override;
     size_t getBytesLength(const key_t& key) const override;
 private:
-    MBRBlockDevice* bd;
     mbed::KVStore* kvstore;
+    MBRBlockDevice* bd;
 };

src/kvstore/kvstore.cpp

@@ -77,6 +77,7 @@ size_t   KVStoreInterface::getString(const key_t& key, char* value, size_t maxLe
 
 #ifdef ARDUINO
 String KVStoreInterface::getString(const key_t& key, const String defaultValue) {
+    (void) defaultValue;
     size_t len = getBytesLength(key);
     char *str = new char[len+1];