ufs: Pass hba pointer to ufshcd_prepare_req_desc_hdr()

Pass the hba pointer itself to ufshcd_prepare_req_desc_hdr()
instead of duplicating utp_transfer_req_desc access at each
call site. No functional change.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Tested-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>