change tft clear() to fillScreen() (#3077)

Maintains compatability with ESPI driver.

Co-authored-by: Jonathan Bennett <jbennett@incomsystems.biz>

src/graphics/TFTDisplay.cpp

@@ -425,7 +425,8 @@ TFTDisplay::TFTDisplay(uint8_t address, int sda, int scl, OLEDDISPLAY_GEOMETRY g
 void TFTDisplay::display(bool fromBlank)
 {
     if (fromBlank)
-        tft->clear();
+        tft->fillScreen(TFT_BLACK);
+    // tft->clear();
     concurrency::LockGuard g(spiLock);
 
     uint16_t x, y;