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>
8 files changed