On MES12, HW can monitor up to 2048 doorbells that not be
mapped currently and trigger the interrupt to MES when these unmapped
doorbell been ringed.
Signed-off-by: shaoyunl <shaoyun.liu@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>