[SCSI] esp: correct module name in Kconfig help for SCSI_SUNESP

The module name was changed from esp to sun_esp some time ago.
Also correct the list of chips supported by the driver.

Signed-off-by: Frans Pop <elendil@planet.nl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>