Revert "scsi: ufs: try read capacity (10) first"

This reverts commit 7d76a33c.
Read capacity (16) is used, in addition to reading capacity, for
reading unmap command parameters. In UFS spec since v2.0 read
capacity (16) command is mandatory for embedded devices.

If read capacity (16) is not supported by the device then it simply
rejects the scsi command with ILLEGAL_REQUEST in sense key. The sd
driver then retries with read capacity (10), thus keeping backward
compatibility.

Change-Id: Iaa2acdfab0d7f0f6e1ef20e370195a3b64068216
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>