dell-laptop: use dell_smbios_find_token() instead of find_token_location()

Replace all uses of find_token_location() with dell_smbios_find_token()
to avoid directly accessing the da_tokens table.

Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>