Merge pull request #2554 from Makuna/SPIFFSFileSeek

Add Arduino File standard seek call

Author: igrr

cores/esp8266/FS.h

@@ -64,6 +64,9 @@ class File : public Stream
     }
     size_t read(uint8_t* buf, size_t size);
     bool seek(uint32_t pos, SeekMode mode);
+    bool seek(uint32_t pos) {
+        return seek(pos, SeekSet);
+    }
     size_t position() const;
     size_t size() const;
     void close();