Add SD host driver for Blackfin BF54x and BF51x.

[akpm@linux-foundation.org: fix layout, c99 warning]
Signed-off-by: NCliff Cai <cliffcai.sh@gmail.com>
Signed-off-by: NBryan Wu <cooloney@kernel.org>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>