mmc: core: Remove redundant runtime_idle callback

The runtime PM core handles a runtime_idle callback set to NULL as one
returning 0. So, let's just set it to NULL instead.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
1 file changed