ACPI: inline trivial acpi_os_get_thread_id()

acpi_os_get_thread_id() is used only for debugging
code that is not enabled on Linux, so stub it out.

Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/include/acpi/platform/aclinux.h b/include/acpi/platform/aclinux.h
index 2f5bb5b..b5655a6 100644
--- a/include/acpi/platform/aclinux.h
+++ b/include/acpi/platform/aclinux.h
@@ -99,4 +99,8 @@
 
 #define acpi_cpu_flags unsigned long
 
+#define acpi_thread_id u32
+
+static inline acpi_thread_id acpi_os_get_thread_id(void) { return 0; }
+
 #endif				/* __ACLINUX_H__ */