Added handling of the case where a single clock source drives multiple route-through BUFHCEs
Added handling of the case where a single clock source drives multiple route-through BUFHCEs

Signed-off-by: Maciej Kurc <572803cc6e8d7bb35033942e4b03254951a2e0d6@antmicro.com>

SymbiFlow/symbiflow-xc-fasm2bels