ACPICA: ACPI 6.0: Add support for XENV table.

ACPICA commit 08c4197cf4ddd45f0c961078220b0fc19c10745c

Xen Environment table.

Link: https://github.com/acpica/acpica/commit/08c4197c
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

include/acpi/actbl3.h

@@ -70,6 +70,7 @@
 #define ACPI_SIG_RASF           "RASF"	/* RAS Feature table */
 #define ACPI_SIG_STAO           "STAO"	/* Status Override table */
 #define ACPI_SIG_TPM2           "TPM2"	/* Trusted Platform Module 2.0 H/W interface table */
+#define ACPI_SIG_XENV           "XENV"	/* Xen Environment table */
 
 #define ACPI_SIG_S3PT           "S3PT"	/* S3 Performance (sub)Table */
 #define ACPI_SIG_PCCS           "PCC"	/* PCC Shared Memory Region */
@@ -729,6 +730,23 @@ struct acpi_tpm2_control {
 	u64 response_address;
 };
 
+/*******************************************************************************
+ *
+ * XENV - Xen Environment Table (ACPI 6.0)
+ *        Version 1
+ *
+ * Conforms to "ACPI Specification for Xen Environment Table" 4 January 2015
+ *
+ ******************************************************************************/
+
+struct acpi_table_xenv {
+	struct acpi_table_header header;	/* Common ACPI table header */
+	u64 grant_table_address;
+	u64 grant_table_size;
+	u32 event_interrupt;
+	u8 event_flags;
+};
+
 /* Reset to default packing */
 
 #pragma pack()