thinkpad-acpi: wrong thermal attribute_group removed in thermal_exit()

sysfs_remove_group() removed the wrong attribute_group for
thermal_read_mode TPEC_8, ACPI_TMP07 and ACPI_UPDT

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Henrique de Moraes Holschuh <ibm-acpi@hmh.eng.br>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>