ACPICA: Add support for 64 bit risc-v compilation

ACPICA commit 0def627be286620c64a5d4d60ce2373f119169a9

Add 64 bit risc-v architecture.  Useful for acpica tools and
incorporating ACPICA into the Firmware Test Suite.

Link: https://github.com/acpica/acpica/commit/0def627b
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Erik Kaneda <erik.kaneda@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
index 987e2af..4098ba1 100644
--- a/include/acpi/platform/aclinux.h
+++ b/include/acpi/platform/aclinux.h
@@ -190,7 +190,8 @@
 
 #if defined(__ia64__)    || (defined(__x86_64__) && !defined(__ILP32__)) ||\
 	defined(__aarch64__) || defined(__PPC64__) ||\
-	defined(__s390x__)
+	defined(__s390x__) ||\
+	(defined(__riscv) && (defined(__LP64__) || defined(_LP64)))
 #define ACPI_MACHINE_WIDTH          64
 #define COMPILER_DEPENDENT_INT64    long
 #define COMPILER_DEPENDENT_UINT64   unsigned long