08f1387933
per-protocol. This reduces the number scsi symbols references by cam_xpt significantly, and eliminates all ata / nvme symbols. There's still some NVME / ATA specific code for dealing with XPT_NVME_IO and XPT_ATA_IO respectively, and a bunch of scsi-specific code, but this is progress. Differential Revision: https://reviews.freebsd.org/D7289