lib/ECP5_RAM: mark interfaces always_ready

Elides a couple of unnecessary signals from the design

lib/ECP5_RAM.bsv

@@ -237,6 +237,7 @@ endfunction
 //
 
 // EBRPort is a port of an EBR memory.
+(* always_ready *)
 interface EBRPort#(type addr, type data);
    method Action put(UInt#(3) chip_select, Bool write, addr address, data datain);
    method data read();