We want to see if the requested start or total block count are
unaligned.  We discard the whole numbers and only care about the
remainder.  Update the code to use div_u64_rem here and add a comment.

Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Cc: Bernhard Nortmann <bernhard.nortmann@web.de>
Reported-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
Tested-by: Bernhard Nortmann <bernhard.nortmann@web.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

The way that struct mmc was implemented was a bit of a mess;
configuration and internal state all jumbled up in a single structure.

On top of that the way initialization is done with mmc_register leads
to a lot of duplicated code in drivers.

Typically the initialization got something like this in every driver.

	struct mmc *mmc = malloc(sizeof(struct mmc));
	memset(mmc, 0, sizeof(struct mmc);
	/* fill in fields of mmc struct */
	/* store private data pointer */
	mmc_register(mmc);

By using the new mmc_create call one just passes an mmc config struct
and an optional private data pointer like this:

	struct mmc = mmc_create(&cfg, priv);

All in tree drivers have been updated to the new form, and expect
mmc_register to go away before long.

Changes since v1:

* Use calloc instead of manually calling memset.
* Mark mmc_register as deprecated.

Signed-off-by: Pantelis Antoniou <panto@antoniou-consulting.com>

For SPL builds this is just dead code since we'll only need to read.
Eliminating it results in a significant size reduction for the SPL
binary, which may be critical for certain platforms where the binary
size is highly constrained.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>