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.
Set SPR data read to 0 if DU not present
cappuccino/lsu: properly handle async reset for atomic_reserve

Based on a suggestion by Andrew Ray
fix part selects for check_way_tag in d/icaches
mor1kx v2.3