staging: fsl-mc: Move irqchip code out of staging

Now that the fsl-mc bus core infrastructure is out of staging, the
remaining irqchip glue code used (irq-gic-v3-its-fsl-mc-msi.c) goes
to drivers/irqchip.

Create new Kconfig option for irqchip code that depends on
FSL_MC_BUS and ARM_GIC_V3_ITS. This ensures irqchip code only
gets built on ARM64 platforms. We can now remove #ifdef
GENERIC_MSI_DOMAIN_OPS as it was only needed for x86.

Signed-off-by: Stuart Yoder <stuyoder@gmail.com>
[rebased, add dpaa2_eth and dpio #include updates]
Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
[rebased, split irqchip to separate patch]
Signed-off-by: Bogdan Purcareata <bogdan.purcareata@nxp.com>
[add Kconfig dependency on ARM_GIC_V3_ITS]
Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>