Formally remove WITH_BSDCONFIG build option and re-generate src.conf.5
NOTE: Should have been inline with revisions 252862 and 254958.
Remove include opt_ofed.h since OFED is unifdef'd.

Pointed out by: glebius
Add support for emulating the byte move instruction "mov r/m8, r8".

This emulation is required when dumping MMIO space via the ddb "examine"
command.
Allow single byte reads of the emulated MSI-X tables. This is not required
by the PCI specification but needed to dump MMIO space from "ddb" in the
guest.