wifi: iwlwifi: pnvm: handle memory descriptor tlv

When PNVM is obtained from UEFI, there's an additional memory
descriptor TLV that has to be handled. It is the same TLV that
holds data in the reduced power tables. Also, in this TLV, the
actual data is located after address and size, so add the
corresponding offset.

Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230606103519.8c5f5ee8e30b.Id1893c9dec140b5ba4abe8a121c2e1a1d121d2d7@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>