ACPICA: Add Arm IORT IWB node definitions

The IORT IUWB node is defined in IORT issue E.g
See https://developer.arm.com/documentation/den0049/eg

Link: acpica/acpica@a90dc2f5380c
Signed-off-by: Jose Marinho <jose.marinho@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/2691130.Lt9SDvczpP@rafael.j.wysocki

Author: jmarinho

include/acpi/actbl2.h

@@ -682,6 +682,7 @@ enum acpi_iort_node_type {
 	ACPI_IORT_NODE_SMMU_V3 = 0x04,
 	ACPI_IORT_NODE_PMCG = 0x05,
 	ACPI_IORT_NODE_RMR = 0x06,
+	ACPI_IORT_NODE_IWB = 0x07,
 };
 
 struct acpi_iort_id_mapping {
@@ -860,6 +861,12 @@ struct acpi_iort_rmr_desc {
 	u32 reserved;
 };
 
+struct acpi_iort_iwb {
+	u64 base_address;
+	u16 iwb_index;		/* Unique IWB identifier matching with the IWB GSI namespace. */
+	char device_name[];	/* Path of the IWB namespace object */
+};
+
 /*******************************************************************************
  *
  * IOVT - I/O Virtualization Table