cappuccino: remove execute_waiting_o/i from module interconnect

Since this signal is only used in ctr_cappuccino and is just the
negation of execute_valid, it makes more sense to generate the
signal internally in this module.
This also seperates the negated stall signals from ctrl stage
into an own public signal.
LSU: Fix bug with lwa and snoop of same address

When a snoop event occurs parallel to the lwa completion, the swa
should fail. This is enabled by this patch that essentially simply
changes the order of checking.
Merge branch 'master' of https://github.com/wallento/mor1kx