sd: use REQ_PM in sd's runtime suspend operation

With the introduction of REQ_PM, modify sd's runtime suspend operation
functions to use that flag so that the operations to put the device into
runtime suspended state(i.e. sync cache and stop device) will not affect
its runtime PM status.

Change-Id: I0fe93acfbfbd01ce265a6dd2df6349ca26598fca
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Git-commit: 9b21493c4520970f8f404e0265f48e37f9cffaf5
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[sthumma@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
3 files changed