ufs-pltfrm: initialize DMA mask for device-tree probed device

The device-tree probed device for ARM doesn't have dev->dma_mask.
So dma_set_mask() for the device doesn't succeed.  The popular trick
for this is - dev->dma_mask = &dev->coherent_dma_mask;

Currently there is no dma_set_mask() call in ufs-pltfrm, but the
forthcoming fix needs proper DMA mask setting in ufs core driver.  So
initializing dev->dma_mask as described above is required.

Conflicts:
	drivers/scsi/ufs/ufshcd-pltfrm.c

Change-Id: I8428f106ca2d97badb7bf57cbb1d3ee14dddaf7f
Signed-off-by: Akinobu Mita <mita@fixstars.com>
Cc: Sujit Reddy Thumma <sthumma@codeaurora.org>
Cc: Vinayak Holikatti <vinholikatti@gmail.com>
Cc: Santosh Y <santoshsy@gmail.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
Cc: linux-scsi@vger.kernel.org
Patch-mainline: linux-scsi@vger.kernel.org @ 2013/08/19 19:26
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
(cherry picked from commit 1b5d6fafbfbd76d669b6deb4ee68679c03aba622)
[subhashj@codeaurora.org: resolved trivial conflicts]
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>