[SCSI] ufshcd: UFS Host controller driver

This patch adds support for Universal Flash Storage(UFS)
host controllers. The UFS host controller driver
includes host controller initialization method.

The Initialization process involves following steps:
 - Initiate UFS Host Controller initialization process by writing
   to Host controller enable register
 - Configure UFS Host controller registers with host memory space
   datastructure offsets.
 - Unipro link startup procedure
 - Check for connected device
 - Configure UFS host controller to process requests
 - Enable required interrupts
 - Configure interrupt aggregation

[jejb: fix warnings in 32 bit compile]
Signed-off-by: Santosh Yaraganavi <santoshsy@gmail.com>
Signed-off-by: Vinayak Holikatti <vinholikatti@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@linaro.org>
Reviewed-by: Vishak G <vishak.g@samsung.com>
Reviewed-by: Girish K S <girish.shivananjappa@linaro.org>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>