soc: qcom: aoss: Fix missing put_device call in qmp_get

The reference taken by 'of_find_device_by_node()' must be released when
not needed anymore.
Add the corresponding 'put_device()' in the error handling paths.

Fixes: 8c75d585b931 ("soc: qcom: aoss: Expose send for generic usecase")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220108095931.21527-1-linmq006@gmail.com
