Create a API header for MSI specific functions which are relevant to device
drivers.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Reviewed-by: NJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: NKevin Tian <kevin.tian@intel.com>
Acked-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221124230313.632679220@linutronix.de