D-Bus: Make WPAS_DBUS_TYPE_BINARRAY value less confusing

D-Bus: Make WPAS_DBUS_TYPE_BINARRAY value less confusing

Commit 911e97e4002019e577bb1086f1fd02daff978544 ('DBus: Refactor array
adding, add binary arrays') introduced WPAS_DBUS_TYPE_BINARRAY as an
internal fake type for array_type. However, it selected this value to be
(DBUS_NUMBER_OF_TYPES + 100) = 116 = 't'. This happens to conflict with
DBUS_TYPE_UINT64 ((int) 't'). While none of the existing array_type use
cases supported UINT64, it is much clearer if WPAS_DBUS_TYPE_BINARRAY
has a value that does not match any existing DBUS_TYPE_* value. Replace
this with '@' (64).

Signed-off-by: Jouni Malinen <j@w1.fi>