iwlwifi: wrt: add mipi type to debug types

This adds the MIPI mode type to the types declared supported
by the driver. Without this patch, when using MIPI mode and
looking at the logs the user would see the debug destination
"UNKNOWN".

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>