Blackfin: bfin_sdh: drop dos part hardcode

No other driver sets up the part type to DOS in their init, and it
doesn't seem to be needed as `mmcinfo` and `mmc part` stll work, so
drop it.

Reported-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

drivers/mmc/bfin_sdh.c

@@ -256,7 +256,6 @@ int bfin_mmc_init(bd_t *bis)
 	mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
 	mmc->f_max = get_sclk();
 	mmc->f_min = mmc->f_max >> 9;
-	mmc->block_dev.part_type = PART_TYPE_DOS;
 
 	mmc->b_max = 0;