irqchip/ls-scfg-msi: Fix typo of MSI compatible strings

The patch is to fix typo of the Layerscape SCFG MSI dts compatible
strings. "1" is replaced by "l".

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Minghuan Lian <Minghuan.Lian@nxp.com>
Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>