drivers/acpi/thermal.c: fix build with CONFIG_DMI=n

drivers/acpi/thermal.c: In function 'acpi_thermal_init':
drivers/acpi/thermal.c:1794: error: 'thermal_dmi_table' undeclared (first use in this function)
drivers/acpi/thermal.c:1794: error: (Each undeclared identifier is reported only once
drivers/acpi/thermal.c:1794: error: for each function it appears in.)

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>