Update ArduionApi to include Print::printf

Instead of duplicating output call in all children, fork ArduinoApi and
add it in the Print base class.

.gitmodules

 [submodule "ArduinoCore-API"]
 	path = ArduinoCore-API
-	url = https://github.com/arduino/ArduinoCore-API.git
+	url = https://github.com/earlephilhower/ArduinoCore-API.git
 [submodule "pico-sdk"]
 	path = pico-sdk
 	url = https://github.com/raspberrypi/pico-sdk.git

ArduinoCore-API @ 8f747a4a

-Subproject commit 2af4a9c721f96b80010caf6923a12809f13026cd
+Subproject commit 8f747a4a5756cbea5123b34bb7f65b043cb80c26

cores/rp2040/SerialUART.h

@@ -51,29 +51,6 @@ public:
     using Print::write;
     operator bool() override;
 
-    // By all rights, this should be in Print.h...
-    size_t printf(const char *format, ...) {
-        va_list arg;
-        va_start(arg, format);
-        char temp[64];
-        char* buffer = temp;
-        size_t len = vsnprintf(temp, sizeof(temp), format, arg);
-        va_end(arg);
-        if (len > sizeof(temp) - 1) {
-            buffer = new char[len + 1];
-            if (!buffer) {
-                return 0;
-            }
-            va_start(arg, format);
-            vsnprintf(buffer, len + 1, format, arg);
-            va_end(arg);
-        }
-        len = write((const uint8_t*) buffer, len);
-        if (buffer != temp) {
-            delete[] buffer;
-        }
-        return len;
-    }
 private:
     bool _running = false;
     uart_inst_t *_uart;

cores/rp2040/SerialUSB.h

@@ -42,30 +42,6 @@ public:
     using Print::write;
     operator bool() override;
 
-    // By all rights, this should be in Print.h...
-    size_t printf(const char *format, ...) {
-        va_list arg;
-        va_start(arg, format);
-        char temp[64];
-        char* buffer = temp;
-        size_t len = vsnprintf(temp, sizeof(temp), format, arg);
-        va_end(arg);
-        if (len > sizeof(temp) - 1) {
-            buffer = new char[len + 1];
-            if (!buffer) {
-                return 0;
-            }
-            va_start(arg, format);
-            vsnprintf(buffer, len + 1, format, arg);
-            va_end(arg);
-        }
-        len = write((const uint8_t*) buffer, len);
-        if (buffer != temp) {
-            delete[] buffer;
-        }
-        return len;
-    }
-
 private:
     bool _running = false;
 };