remoteproc: qcom: q6v5: Propagate EPROBE_DEFER

In the case that the interrupts fail to result because of the
interrupt-controller not yet being registered the
platform_get_irq_byname() call will fail with -EPROBE_DEFER, but passing
this into devm_request_threaded_irq() will result in -EINVAL being
returned, the driver is therefor not reprobed later.

Fixes: 3b415c8f ("remoteproc: q6v5: Extract common resource handling")
Cc: stable@vger.kernel.org
Reviewed-by: Sibi Sankar <sibis@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>