dts: bindings: mpu: add PPB and IO regions

Extends zephyrproject-rtos#43119 with PPB and IO values of
`memory-region-mpu`.

That allows MPU region definition with
PPB or IO attributes in the DTS.

Signed-off-by: Georgij Cernysiov <[email protected]>

Author: GeorgeCGV

dts/bindings/base/zephyr,memory-region.yaml

@@ -24,6 +24,8 @@ properties:
       - "RAM"
       - "RAM_NOCACHE"
       - "FLASH"
+      - "PPB"
+      - "IO"
     description: |
       Signify that this node should result in a dedicated MPU region. The
       region address and size are taken from the <reg> property, while the MPU

include/zephyr/linker/devicetree_regions.h

@@ -224,19 +224,23 @@
  * to the MPU_FN macro using the 'attr' parameter, in the form
  * REGION_{attr}_ATTR.
  *
- * Currently only three enums are supported for the 'zephyr,memory-region-mpu'
+ * The following enums are supported for the 'zephyr,memory-region-mpu'
  * property:
  *
  *  - RAM
  *  - RAM_NOCACHE
  *  - FLASH
+ *  - PPB
+ *  - IO
  *
  * This means that usually the arch code would provide some macros or defines
  * with the same name of the extended property, that is:
  *
  *  - REGION_RAM_ATTR
  *  - REGION_RAM_NOCACHE_ATTR
  *  - REGION_FLASH_ATTR
+ *  - REGION_PPB_ATTR
+ *  - REGION_IO_ATTR
  *
  * Example devicetree fragment:
  *
@@ -249,6 +253,10 @@
  *             };
  *     };
  *
+ * For detailed information about MPU region attribute define configuration refer
+ * to the specific architecture MPU header.
+ * For example: include/zephyr/arch/arm/aarch32/mpu/arm_mpu_v7m.h.
+ *
  * The 'attr' parameter of the MPU_FN function will be the extended
  * 'REGION_RAM_NOCACHE_ATTR' token and the arch code will be usually
  * implementing a macro with the same name.