remoteproc: qcom: Fix potential device node leaks

Add missing of_node_put()s at two places for device nodes returned by
of_parse_phandle().

Fixes: 051fb70f

 ("remoteproc: qcom: Driver for the self-authenticating
 Hexagon v5")
Signed-off-by: Tobias Jordan <Tobias.Jordan@elektrobit.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>