doc: peripherals: add hwspinlock documentation

Include doxygen documentation of hwspinlock in peripherals.

Signed-off-by: Pierrick Guillaume <pguillaume@fymyte.com>

Author: Fymyte

doc/hardware/peripherals/hwspinlock.rst

@@ -0,0 +1,21 @@
+.. _hwspinlock_api:
+
+Hardware Spinlocks (HWSPINLOCK)
+###############################
+
+Overview
+********
+
+An HWSPINLOCK device is a peripheral used to protect shared resources across clusters in the system.
+Each HWSPINLOCK instance is providing one or more spinlocks. The api is similar to regular zephyr spinlocks.
+
+.. doxygengroup:: spinlock_apis
+
+Because we also want to protect the spinlock resource to be used by multiple cores in the same
+cluster, each HWSPINLOCK device include a regular zephyr spinlock, and use it to lock the access to
+HWSPINLOCK hardware.
+
+API Reference
+*************
+
+.. doxygengroup:: hwspinlock_interface

doc/hardware/peripherals/index.rst

@@ -35,6 +35,7 @@ Peripherals
    gpio.rst
    haptics.rst
    hwinfo.rst
+   hwspinlock.rst
    i2c_eeprom_target.rst
    i3c.rst
    i2c.rst