New kernel drivers and device migrations (#563)

Devices/unphone/source/drivers/unphone_power_switch.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdbool.h>
+
+#include <tactility/device.h>
+#include <tactility/drivers/gpio.h>
+#include <tactility/error.h>
+
+struct UnphonePowerSwitchConfig {
+    struct GpioPinSpec pin;
+};
+
+/** @brief Reads whether the physical power switch is currently in the "on" position. */
+error_t unphone_power_switch_is_on(struct Device* device, bool* on);
+
+/**
+ * @brief Arms deep-sleep wakeup so the device wakes when the switch moves to "on".
+ * Only applies to the deep sleep entered right after this call.
+ */
+error_t unphone_power_switch_enable_wake(struct Device* device);
+
+#ifdef __cplusplus
+}
+#endif