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>

drivers/hwmon/acpi_power_meter.c

@@ -973,7 +973,7 @@ static int __init enable_cap_knobs(const struct dmi_system_id *d)
 	return 0;
 }
 
-static struct dmi_system_id __initdata pm_dmi_table[] = {
+static const struct dmi_system_id pm_dmi_table[] __initconst = {
 	{
 		enable_cap_knobs, "IBM Active Energy Manager",
 		{