[SCSI] esp: Correct chip ID probing sequence.

The features enable bit has to be set in the config2 register
before we can be absolutely sure we will probe a correct
part unique ID and family code from the transfer-count-high
register.

Also, reload the CFACT, STP, SOFF, and TIMEO near the end of
esp_reset_esp().

From a patch by Maciej W. Rozycki.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>