mmc: tmio: fixup compile error

This patch fixes the below compile error:

${LINUX}/drivers/mmc/host/tmio_mmc.c: In function 'tmio_mmc_probe':
${LINUX}/drivers/mmc/host/tmio_mmc.c:93:35: \
	error: 'res_ctl' undeclared (first use in this function)
${LINUX}/drivers/mmc/host/tmio_mmc.c:93:35: \
	note: each undeclared identifier is reported only \
	once for each function it appears in

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Chris Ball <chris@printf.net>