[TF-A] [RFC]: UFS patches

Hi all,

We made a few changes to the UFS driver. The proposed patches are posted here: https://review.trustedfirmware.org/q/topic:%22ufs_patches%22+(status:open%20...) .

The patches mainly consist of the below changes: 1. Delete asserts. Return error values instead. 2. Add retry logic and timeouts. 3. Reuse ufshc_send_uic_cmd() for DME_GET and DME_SET commands.

Any feedback/comments on these patches would be greatly appreciated.

Thanks! Jorge Troncoso