mmc: Add a execute_tuning() callback to the mmc operations.

Tuning is a mandatory step in the initialization of SDR104 and HS200 modes.
This callback execute the tuning process.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
3 files changed