doc: reference: Add hwinfo API

Add the hwinfo API to the reference documentation.

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>

doc/reference/peripherals/hwinfo.rst

@@ -0,0 +1,23 @@
+.. _hwinfo_api:
+
+Hardware Information
+####################
+
+Overview
+********
+
+The HW Info API provides access to hardware information such as device
+identifiers.
+
+Configuration Options
+*********************
+
+Related configuration options:
+
+* :option:`CONFIG_HWINFO`
+
+API Reference
+*************
+
+.. doxygengroup:: hwinfo_interface
+   :project: Zephyr

doc/reference/peripherals/index.rst

@@ -14,6 +14,7 @@ Peripherals
    flash.rst
    gna.rst
    gpio.rst
+   hwinfo.rst
    i2c_eeprom_slave.rst
    i2c.rst
    i2s.rst

include/drivers/hwinfo.h

@@ -13,6 +13,13 @@
 #ifndef ZEPHYR_INCLUDE_DRIVERS_HWINFO_H_
 #define ZEPHYR_INCLUDE_DRIVERS_HWINFO_H_
 
+/**
+ * @brief Hardware Information Interface
+ * @defgroup hwinfo_interface Hardware Info Interface
+ * @ingroup io_interfaces
+ * @{
+ */
+
 #include <zephyr/types.h>
 #include <sys/types.h>
 #include <stddef.h>
@@ -23,12 +30,6 @@
 extern "C" {
 #endif
 
-/**
- * @brief Device ID
- * @{
- */
-
-
 /**
  * @brief Copy the device id to a buffer
  *