scsi: ufs-qcom: save ufs_qcom_host object pointers

Analyzing crash logs is made easier when the different UFS objects
state is accessible. Save a pointer to the main ufs_qcom_host
object when it is allocated.

Change-Id: I8eb909729dee7209e5d9b1af2652fe76ccd3c0ca
Signed-off-by: Gilad Broner <gbroner@codeaurora.org>