[SCSI] esas2r: Fixes for big-endian platforms

In esas2r_format_init_msg(), sgl_page_size and epoch_time params
are converted to little endian and the firmware version read from
the hba is converted to cpu endianess.

In esas2r_rq_init_request, correct and simplify the construction
of the SCSI handle.

These fixes are the result of testing on a PPC64 machine.

Signed-off-by: Bradley Grove <bgrove@attotech.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>