Fix I2C initialization

[Sl-Alex]

There are two prototypes for Wire.begin():

   bool begin(int sda=-1, int scl=-1, uint32_t frequency=0); // returns true, if successful init of i2c bus
   bool begin(uint8_t slaveAddr, int sda=-1, int scl=-1, uint32_t frequency=0);

The problem is that if we call Wire.begin(m_sda, m_scl) then the second (I2C slave) constructor is called (at least this was my case).
If we set pins expicitly and then call Wire.begin() without parameters then there is no ambiguity, the first constructor will be called.

[geraballz]

This commit works very well

[domdfcoding]

I wish I'd seen this half an hour ago before going down the rabbit hole of figuring out why the touchscreen doesn't work. 🤦‍

[ltruelove]

This also fixed my issue with not registering touches and constant warnings from the Wire library in the serial monitor.

[iBobik]

Touches in the 3D cube demo works, but in the lvgl demo taps to the buttons do nothing.

I enabled TOUCHSCREEN_DEBUG and I see touches logged.