genirq/msi: Rename IRQ_DOMAIN_MSI_REMAP to IRQ_DOMAIN_ISOLATED_MSI

What x86 calls "interrupt remapping" is one way to achieve isolated MSI,
make it clear this is talking about isolated MSI, no matter how it is
achieved. This matches the new driver facing API name of
msi_device_has_isolated_msi()

No functional change.

Link: https://lore.kernel.org/r/6-v3-3313bb5dd3a3+10f11-secure_msi_jgg@nvidia.com


Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>