PCI: brcmstb: Fix missing of_node_put() in brcm_pcie_probe()

PCI: brcmstb: Fix missing of_node_put() in brcm_pcie_probe()

A call to of_parse_phandle() is incrementing the refcount, and as such,
the of_node_put() must be called when the reference is no longer needed.

Thus, refactor the existing code and add a missing of_node_put() call
following the check to ensure that "msi_np" matches "pcie->np" and after
MSI initialization, but only if the MSI support is enabled system-wide.

Cc: stable@vger.kernel.org # v5.10+
Fixes: 40ca1bf580ef ("PCI: brcmstb: Add MSI support")
Signed-off-by: Stanimir Varbanov <svarbanov@suse.de>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20250122222955.1752778-1-svarbanov@suse.de
[kwilczynski: commit log]
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>