drivers: mmc: Change datatype of tuning_loop_counter to int

drivers: mmc: Change datatype of tuning_loop_counter to int

tuning_loop_counter is of char type, which is not capable of handling
the entire data range of this variable. This is pointed by below sparse
warning. Change datatype to int to fix this.
warning: comparison is always false due to limited range of data type.

Signed-off-by: Algapally Santosh Sagar <santoshsagar.algapally@amd.com>
Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
Link: https://lore.kernel.org/r/20230120053617.32463-5-ashok.reddy.soma@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>