sh: fix SD / MMC configuration dependencies on ecovec

Update CONFIG_MMC_TMIO to the new CONFIG_MMC_SDHI symbol and fix
MMCIF to also function in modular builds for ecovec.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Simon Horman <horms@verge.net.au>
Cc: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>