feat(legacy): report EMULATOR vendor in legacy

legacy/firmware/fsm_msg_common.h

@@ -19,6 +19,9 @@
 
 bool get_features(Features *resp) {
   resp->has_fw_vendor = true;
+#if EMULATOR
+  strlcpy(resp->fw_vendor, "EMULATOR", sizeof(resp->fw_vendor));
+#else
   const image_header *hdr =
       (const image_header *)FLASH_PTR(FLASH_FWHEADER_START);
   if (SIG_OK == signatures_new_ok(hdr, NULL)) {
@@ -26,6 +29,7 @@ bool get_features(Features *resp) {
   } else {
     strlcpy(resp->fw_vendor, "UNSAFE, DO NOT USE!", sizeof(resp->fw_vendor));
   }
+#endif
   resp->has_vendor = true;
   strlcpy(resp->vendor, "trezor.io", sizeof(resp->vendor));
   resp->major_version = VERSION_MAJOR;