toshiba_acpi: Remove the position sysfs entry

Now that we have proper support for the acceleromeer under the IIO
subsystem, the _position_ sysfs file is now deprecated.

This patch removes all code related to the position sysfs entry.

Signed-off-by: Azael Avalos <coproscefalo@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>