Add important pin definitions to Controllino.h

[pmmarquez]

There are some some important pins not present in Controllino.h that simplify some examples and library functions that are currently made with register manipulation, this pins are available in the BSP pin definitions: hardware/avr/VERSION/variants/Controllino_mega/pins_arduino.h

  PE  , // PE 6 ** 71 ** CONTROLLINO ETHERNET INTERRUPT
  PJ  , // PJ 7 ** 73 ** CONTROLLINO RTC INTERRUPT
  PE  , // PE 7 ** 74 ** CONTROLLINO OVERLOAD
  PJ  , // PJ 6 ** 75 ** CONTROLLINO RS485 DE
  PJ  , // PJ 5 ** 76 ** CONTROLLINO RS485 /RE
  PD  , // PD 4 ** 77 ** CONTROLLINO MEGA Digital 20
  PD  , // PD 5 ** 78 ** CONTROLLINO MEGA Digital 21
  PD  , // PD 6 ** 79 ** CONTROLLINO MEGA Digital 22
  PJ  , // PJ 4 ** 80 ** CONTROLLINO MEGA Digital 23

[CONTROLLINO-Support]

All necessary pin definitions are already there, like these `#define CONTROLLINO_ETHERNET_CHIP_SELECT 70

define CONTROLLINO_ETHERNET_INTERRUPT 71

define CONTROLLINO_RTC_CHIP_SELECT 72

define CONTROLLINO_RTC_INTERRUPT 73

define CONTROLLINO_OVERLOAD 74

define CONTROLLINO_RS485_DE 75

define CONTROLLINO_RS485_nRE 76`

Issue to be closed.