tmio_mmc: Keep card-detect interrupts enabled

On SuperH platforms the SDHI controller does not produce any command IRQs after
a completed IO. This leads to card-detect interrupts staying disabled. Do not
disable card-detect interrupts on DATA IRQs.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>