remoteproc: qcom: wcnss: Fix handling of IRQs

The wcnss_get_irq function is expected to return a value > 0 in the
event that an IRQ is succssfully obtained, but it instead returns 0.
This causes the stop and ready IRQs to never actually be used despite
being defined in the device-tree. This patch fixes that.

Fixes: aed361ad ("remoteproc: qcom: Introduce WCNSS peripheral image loader")
Signed-off-by: Sireesh Kodali <sireeshkodali1@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220526141740.15834-2-sireeshkodali1@gmail.com