mmc: sdio: fix SDIO suspend/resume regression

Fix SDIO suspend/resume regression introduced by 4c2ef25f "mmc: fix
all hangs related to mmc/sd card insert/removal during suspend/resume":

  PM: Syncing filesystems ... done.
  Freezing user space processes ... (elapsed 0.01 seconds) done.
  Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
  Suspending console(s) (use no_console_suspend to debug)
  pm_op(): platform_pm_suspend+0x0/0x5c returns -38
  PM: Device pxa2xx-mci.0 failed to suspend: error -38
  PM: Some devices failed to suspend

4c2ef25f moved the card removal/insertion mechanism out of MMC's
suspend/resume path and into pm notifiers (mmc_pm_notify), and that
broke SDIO's expectation that mmc_suspend_host() will remove the card,
and squash the error, in case -ENOSYS is returned from the bus suspend
handler (mmc_sdio_suspend() in this case).

mmc_sdio_suspend() is using this whenever at least one of the card's SDIO
function drivers does not have suspend/resume handlers - in that case
it is agreed to force removal of the entire card.

This patch fixes this regression by trivially bringing back that part of
mmc_suspend_host(), which was removed by 4c2ef25f.
Reported-and-tested-by: Sven Neumann <s.neumann@raumfeld.com>
Signed-off-by: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: <stable@kernel.org>
Acked-by: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/core/core.c

@@ -1631,6 +1631,19 @@ int mmc_suspend_host(struct mmc_host *host)
 	if (host->bus_ops && !host->bus_dead) {
 		if (host->bus_ops->suspend)
 			err = host->bus_ops->suspend(host);
+		if (err == -ENOSYS || !host->bus_ops->resume) {
+			/*
+			 * We simply "remove" the card in this case.
+			 * It will be redetected on resume.
+			 */
+			if (host->bus_ops->remove)
+				host->bus_ops->remove(host);
+			mmc_claim_host(host);
+			mmc_detach_bus(host);
+			mmc_release_host(host);
+			host->pm_flags = 0;
+			err = 0;
+		}
 	}
 	mmc_bus_put(host);