mmc: fix the use of kunmap_atomic() in tmio_mmc.h

kunmap_atomic() takes the cookie, returned by the kmap_atomic() as its
argument and not the page address, used as an argument to kmap_atomic().
This patch fixes the compile error:

In file included from drivers/mmc/host/tmio_mmc.c:37:
drivers/mmc/host/tmio_mmc.h: In function 'tmio_mmc_kunmap_atomic':
drivers/mmc/host/tmio_mmc.h:192: error: negative width in bit-field '<anonymous>'

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Tested-by: Magnus Damm <damm@opensource.se>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>