scsi: dc395x: remove dc395x_bios_param

dc395x_bios_param was only different from the default when the
CONFIG_SCSI_DC395x_TRMS1040_TRADMAP symbol is true, but that symbol doesn't
exist in the Kconfig system and thus can't be set.

Link: https://lore.kernel.org/r/20200325105505.1028582-1-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>