MCP3204 4-channel 12-bit ADC component (#2895)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

esphome/components/mcp3204/sensor/mcp3204_sensor.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "esphome/components/sensor/sensor.h"
+#include "esphome/components/voltage_sampler/voltage_sampler.h"
+#include "esphome/core/component.h"
+#include "esphome/core/hal.h"
+
+#include "../mcp3204.h"
+
+namespace esphome {
+namespace mcp3204 {
+
+class MCP3204Sensor : public PollingComponent,
+                      public Parented<MCP3204>,
+                      public sensor::Sensor,
+                      public voltage_sampler::VoltageSampler {
+ public:
+  MCP3204Sensor(uint8_t pin);
+
+  void update() override;
+  void dump_config() override;
+  float get_setup_priority() const override;
+  float sample() override;
+
+ protected:
+  uint8_t pin_;
+};
+
+}  // namespace mcp3204
+}  // namespace esphome