Fix ICDP Long Write command

Change the extra pre-read latency from READ_TO_WRITE_DELAY to
(READ_TO_WRITE_DELAY - BL/2) for pre-read data won't be sent on data
bus, and the burst latency can be overlapped by the following write
delay.
write with pre-read method not work

The method of writing with pre-read operation has something worng with
its timing which I have no time to debug. The pre-read method will be
deprecated.The Long Write method will replece it instead.
1.ICDP_LONG_WRITE/ICDP_PRE_READ code isolation. 2.Add Debug Switch
DEBUG_TRANS_LATENCY
Faults-injection based on Possion Random Generator