mmc: fix au1xmmc build error

This patch has fixed the following build error abou au1xmmc.

drivers/mmc/au1xmmc.c: In function `au1xmmc_poll_event':
drivers/mmc/au1xmmc.c:835: warning: unused variable `status'
drivers/mmc/au1xmmc.c: At top level:
drivers/mmc/au1xmmc.c:878: error: parse error before "const"
drivers/mmc/au1xmmc.c: In function `au1xmmc_probe':
drivers/mmc/au1xmmc.c:909: error: `au1xmmc_ops' undeclared (first use in this function)
drivers/mmc/au1xmmc.c:909: error: (Each undeclared identifier is reported only once
drivers/mmc/au1xmmc.c:909: error: for each function it appears in.)
drivers/mmc/au1xmmc.c: At top level:
drivers/mmc/au1xmmc.c:659: warning: 'au1xmmc_request' defined but not used
drivers/mmc/au1xmmc.c:719: warning: 'au1xmmc_set_ios' defined but not used
make[2]: *** [drivers/mmc/au1xmmc.o] Error 1
make[1]: *** [drivers/mmc] Error 2
make: *** [drivers] Error 2

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>