scsi: ufs: expose driver run time data and hci regs via debugfs

This change adds a few more options to a user to get a complete
status and statistics regarding the UFS driver, via debugfs
This information includes:
1. UFS Host Controller registers (cat /sys/kernel/debug/ufs/host_regs)
2. hba values (cat /sys/kernel/debug/ufs/show_hba)

Change-Id: Iac60de81a56ed42de72c3a7946a0d2bb5fab2903
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>