dmi: Mark all struct dmi_system_id instances const

... and __initconst if applicable.

Based on similar work for an older kernel in the Grsecurity patch.

[JD: fix toshiba-wmi build]
[JD: add htcpen]
[JD: move __initconst where checkscript wants it]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
diff --git a/drivers/platform/x86/ibm_rtl.c b/drivers/platform/x86/ibm_rtl.c
index 610ac83..18d55ce 100644
--- a/drivers/platform/x86/ibm_rtl.c
+++ b/drivers/platform/x86/ibm_rtl.c
@@ -227,7 +227,7 @@ static void rtl_teardown_sysfs(void) {
 }
 
 
-static struct dmi_system_id __initdata ibm_rtl_dmi_table[] = {
+static const struct dmi_system_id ibm_rtl_dmi_table[] __initconst = {
 	{                                                  \
 		.matches = {                               \
 			DMI_MATCH(DMI_SYS_VENDOR, "IBM"),  \