mmc: tmio: remove broken and noisy debug macro

Some change for v4.14 broke the debug output for TMIO. But since it was
not helpful to me and too noisy for my taste anyhow, let's just remove
it instead of fixing it. We'll find something better if we'd need it...

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>