platform/x86: dell-laptop: Removed duplicates in DMI whitelist

Fixed a mistake in which several entries were duplicated in the DMI list
from the below commit
fe486138

 platform/x86: dell-laptop: Add 2-in-1 devices to the DMI whitelist

Signed-off-by: Alexander Abrosimov <alexander.n.abrosimov@gmail.com>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>