scsi: ufs: fix endianness sparse warnings

Fix many warnings with incorrect endian assumptions
which makes the code unportable to new architectures.

The UFS specification defines the byte order as big-endian
for UPIU structure and little-endian for the host controller
transfer/task management descriptors.

Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>