PCI: qcom-ep: Treat unknown IRQ events as an error

Sometimes, the Qcom PCIe EP controller can receive some interrupts
unknown to the driver, like safety interrupts in newer SoCs. In those
cases, if the driver doesn't clear the interrupts, it will end up in an
interrupt storm. However, the users will not know about it because the
log is treated as a debug message.

So let's treat the unknown event log as an error so that it at least
makes the user aware, thereby getting fixed eventually.

[kwilczynski: commit log]
Link: https://lore.kernel.org/linux-pci/20230726152931.18134-1-manivannan.sadhasivam@linaro.org
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>