mmc: Do not pass external mmc_cmd structure to mmc_send_op_cond_iter()

mmc: Do not pass external mmc_cmd structure to mmc_send_op_cond_iter()

The previous change to use 'ocr' structure field for storing send_op_cond
command response also stopped using command response directly
outside of mmc_send_op_cond_iter(). Now it becomes possible to use
command structure in mmc_send_op_cond_iter() locally, removing a necessity
to pass it as an argument from the caller.

Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>