reset: starfive: jh71x0: Fix accessing the empty member on JH7110 SoC

In the Linux kernel, the following vulnerability has been resolved: reset: starfive: jh71x0: Fix accessing the empty member on JH7110 SoC data->asserted will be NULL on JH7110 SoC since commit 82327b127d41 ("reset: starfive: Add StarFive JH7110 reset driver") was added. Add the judgment condition to avoid errors when calling reset_control_status on JH7110 SoC.