mmc: sdhci: Constify sdhci_ops structs where possible

Basically all drivers can have sdhci_ops struct const, but almost none do.
This patch constifies all sdhci_ops struct declarations where possible.

The patch was auto-generated with the following coccinelle semantic patch:

// <smpl>
@r1@
identifier ops;
identifier fld;
@@
ops.fld = ...;

@disable optional_qualifier@
identifier ops != r1.ops;
@@
static
+const
struct sdhci_ops ops = { ... };
// </smpl>

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>