This patch adds lock to fix comcurrency between tx/rx
to fix 'rockchip-i2s ff070000.i2s; fail to clear'

Considering the situation;

       tx stream              rx stream
           |                      |
           |                   disable
         enable                   |
           |                    reset

After this patch:

         lock
           |
       tx stream
           |
         enable
           |
        unlock
       --------               ---------
                                lock
                                  |
                              rx stream
                                  |
                               disable
                                  |
                                reset
                                  |
                               unlock
Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Link: https://lore.kernel.org/r/1630674434-650-1-git-send-email-sugar.zhang@rock-chips.comSigned-off-by: Mark Brown <broonie@kernel.org>