i2c-support: Refactor to use variants pinmap

* Now the o2c_dev is defined in the XX_pinmap.h file in variants so we now have abstraction.
This way there should not be a need for the user while adding new board support to modify or
tweak the Wire library.

* Replace double quotes (") with angel braces because we have a proper CMake structure
that takes care of all the include locations for us.

* Move a few includes from the Wire library into the arduino...pinmap.h file since
we need to create the i2c_dev over there.

* Delete unused variables inside Wire.h like rxRingBuffer and i2c_dev and bus.

Signed-off-by: Dhruva Gole <[email protected]>

Author: DhruvaG2000

libraries/Wire/Wire.cpp

@@ -1,7 +1,6 @@
 #include <Wire.h>
 
 void arduino::ZephyrI2C::begin() {
-  i2c_dev = DEVICE_DT_GET(DT_NODELABEL(i2c0));
   ring_buf_init(&rxRingBuffer.rb, sizeof(rxRingBuffer.buffer), rxRingBuffer.buffer);
 }
 
@@ -75,7 +74,7 @@ int arduino::ZephyrI2C::read() {
         }
 		return (int)buf[0];
   }
-  return rxBuffer[0];
+  return EXIT_FAILURE;
 }
 
 int arduino::ZephyrI2C::available() { // TODO for ADS1115 

libraries/Wire/Wire.h

@@ -1,10 +1,8 @@
 #pragma once
 
-#include "api/ArduinoAPI.h"
-#include "api/HardwareI2C.h"
-#include "api/Print.h"
-#include <zephyr/drivers/i2c.h>
-#include <zephyr/device.h>
+#include <Arduino.h>
+#include <api/HardwareI2C.h>
+#include <api/Print.h>
 #include <zephyr/sys/ring_buffer.h>
 
 typedef void (*voidFuncPtrParamInt)(int);
@@ -36,12 +34,10 @@ class ZephyrI2C : public HardwareI2C {
   virtual int peek();
   virtual void flush();
   virtual int available();
-  const struct device *i2c_dev;
-  static struct i2c_dt_spec bus;
 
 private:
   int _address;
-  uint8_t txBuffer[256], rxBuffer[256];
+  uint8_t txBuffer[256];
   uint32_t usedTxBuffer;
   struct rx_ring_buf{
     struct ring_buf rb;

variants/arduino_nano_33_iot/arduino_nano_33_iot_pinmap.h

@@ -8,6 +8,8 @@
 #pragma once
 #include <zephyr/drivers/gpio.h>
 #include <zephyr/zephyr.h>
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/device.h>
 
 #define LED_BUILTIN 13
 
@@ -79,4 +81,6 @@ enum digitalPins {
   D19,
   D20,
   D21
-};
+};
+
+const static struct device *i2c_dev = DEVICE_DT_GET(DT_NODELABEL(i2c0));