mmc: constify mmc_host_ops vectors

Now that mmc_host_ops can be constified, update the various drivers
to constify those method tables and shrink the writable data segment.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/wbsd.c b/drivers/mmc/wbsd.c
index ced309b..7e040eb 100644
--- a/drivers/mmc/wbsd.c
+++ b/drivers/mmc/wbsd.c
@@ -1021,7 +1021,7 @@
 	return csr & WBSD_WRPT;
 }
 
-static struct mmc_host_ops wbsd_ops = {
+static const struct mmc_host_ops wbsd_ops = {
 	.request	= wbsd_request,
 	.set_ios	= wbsd_set_ios,
 	.get_ro		= wbsd_get_ro,