If MSI is disabled, there's no need to program PCIE_MSI_INTR0_MASK
and PCIE_MSI_INTR0_ENABLE registers.

Link: https://lore.kernel.org/r/20201009155436.27e67238@xhacker.debianSigned-off-by: NJisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Acked-by: NGustavo Pimentel <gustavo.pimentel@synopsys.com>