Revert "iwlwifi: allow memory debug TLV to specify the memory type"

This reverts the addition of memory type in the memory debug TLV
as the firmware never ended up implementing it, and now the PRPH
dump is added as a different TLV.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>