Wire: limit I2C_BUFFER_LENGTH to 255

The fsp i2c implementation cannot send 256 bytes in a single shot, so avoid the corner case

Fixes bug on Adafruit_SSD1306


Former-commit-id: 32282cf

Author: facchinm

libraries/Wire/Wire.h

@@ -56,7 +56,7 @@ using I2C_onRxCallback_f        = void (*)(int);
 using I2C_onTxCallback_f        = void (*)(void);
 
 
-#define I2C_BUFFER_LENGTH      256
+#define I2C_BUFFER_LENGTH      255
 
 #define TWOWIRE_MAX_I2C_CHANNELS (3)  // IIC0 to IIC2
 #define TWOWIRE_MAX_SCI_CHANNELS (10) // SCI0 to SCI9