The register based interrupts infrastructure does not scale
efficiently to allow delivering interrupts to a large number
of virtual machines. Memory based interrupt reporting provides
an efficient and scalable infrastructure.

Define handler to read and dispatch memory based interrupts.
We will use this handler in upcoming patch.

Cc: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://lore.kernel.org/r/20231214185955.1791-8-michal.wajdeczko@intel.comSigned-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>