lsu: reset state for write pending

Define the store_buffer_write_pending signal to be low after reset.
lsu: add missing signal definition

dc_refill_req was not properly defined if the cache is deactivated.
cappuccino/ctrl: do not copy FO from esr on rfe

The FO (fixed one) bit should always be set to one,
allowing it to be altered through esr is not allowed.