[SCSI] ufs: Segregate PCI Specific Code

This patch segregates the PCI specific code in ufshcd.c to make it
ready for splitting into core ufs driver and PCI glue driver. Also
copyright header modification to remove extra warranty disclaim.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Tested-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Vinayak Holikatti <vinholikatti@gmail.com>
Signed-off-by: Santosh Yaraganavi <santoshsy@gmail.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>