mmc: sh_mmcif: Use response type to know when to enable busy detection

The sh_mmcif explicity checks for certain commands to decide when to
enable HW busy detection. Instead, it should only check the response type
as it tells if busy detection is needed.

In this way, the mmc core also gets full control whether it thinks busy
detection should be done or not. In some specific scenarios, like for
ERASE and STOP commands it may decide to fall back to use a CMD13 to poll
the card status instead.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>