remoteproc: sysmon: fix memory leak in qcom_add_sysmon_subdev()

The kfree() should be called when of_irq_get_byname() fails or
devm_request_threaded_irq() fails in qcom_add_sysmon_subdev(),
otherwise there will be a memory leak, so add kfree() to fix it.

Fixes: 027045a6 ("remoteproc: qcom: Add shutdown-ack irq")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221129105650.1539187-1-cuigaosheng1@huawei.com