Small fifo hardened power consumption

[gaozihou]

Feedback from @tommydcjung:
r_v_i is on almost all the time, which isn't a functional bug, but it would be wasting energy.

[taylor-bsg]

maybe tag the specific line of code?

[gaozihou]

Here is the line:

basejump_stl/bsg_dataflow/bsg_fifo_1r1w_small_hardened.v

Line 99 in e68cdde

,.r_v_i (~read_write_same_addr_n)

Currently it keeps reading from the RAM. Ideally we could read only once and store data into the bypass register