mmc: Allow host drivers to specify a max block size

Most controllers have an upper limit on the block size. Allow the host
drivers to specify this and make sure we avoid hitting this limit.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/drivers/mmc/omap.c b/drivers/mmc/omap.c
index d30540b..fa69a0d 100644
--- a/drivers/mmc/omap.c
+++ b/drivers/mmc/omap.c
@@ -1099,6 +1099,7 @@
 	 */
 	mmc->max_phys_segs = 32;
 	mmc->max_hw_segs = 32;
+	mmc->max_blk_size = 2048;	/* BLEN is 11 bits (+1) */
 	mmc->max_sectors = 256; /* NBLK max 11-bits, OMAP also limited by DMA */
 	mmc->max_seg_size = mmc->max_sectors * 512;