mmc: cb710: drop free_irq for devm_request_irq allocated irq

irq allocated with devm_request_irq should not be freed using
free_irq, because doing so causes a dangling pointer, and a
subsequent double free.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>