feat(drivers): add driver for MAX17048 fuel gauge

Add driver for MAX17048 fuel gauge for battery reporting.

app/module/drivers/sensor/max17048/max17048.h

@@ -0,0 +1,41 @@
+/*
+ * Copyright (c) 2022 The ZMK Contributors
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#pragma once
+
+#include <zephyr/device.h>
+#include <zephyr/sys/util.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define REG_VCELL 0x02
+#define REG_STATE_OF_CHARGE 0x04
+#define REG_MODE 0x06
+#define REG_VERSION 0x08
+#define REG_HIBERNATE 0x0A
+#define REG_CONFIG 0x0C
+#define REG_VALERT 0x14
+#define REG_CHARGE_RATE 0x16
+#define REG_VRESET 0x18
+#define REG_STATUS 0x1A
+
+struct max17048_config {
+    struct i2c_dt_spec i2c_bus;
+};
+
+struct max17048_drv_data {
+    struct k_sem lock;
+
+    uint16_t raw_state_of_charge;
+    uint16_t raw_charge_rate;
+    uint16_t raw_vcell;
+};
+
+#ifdef __cplusplus
+}
+#endif