ufs-qcom: add support for Qualcomm Technologies Inc platforms

This change adds support for Qualcomm Technologies Inc platforms that
use UFS driver. for example, it adds :
- PM specific operations during hibern8, suspend, resume, clock setup
- qcom-ufs generic phy driver initialization, calibration,
  power-on/off sequence, etc.
- UFS Controller specific configuration
- Rate, Gear, Mode negotiation between device and controller

Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Reviewed-by: Dov Levenglick <dovl@codeaurora.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>