Fix subghz remote api symbols (#175)

lib/subghz/protocols/secplus_v2.h

@@ -1,6 +1,10 @@
 #pragma once
 #include "base.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define SUBGHZ_PROTOCOL_SECPLUS_V2_NAME "Security+ 2.0"
 
 typedef struct SubGhzProtocolDecoderSecPlus_v2 SubGhzProtocolDecoderSecPlus_v2;
@@ -133,3 +137,7 @@ SubGhzProtocolStatus
  * @param output Resulting text
  */
 void subghz_protocol_decoder_secplus_v2_get_string(void* context, FuriString* output);
+
+#ifdef __cplusplus
+}
+#endif