Centralize compat support for PCIOCGETCONF.

[brooks]

Summary

The pre-7 compat for both native and 32-bit code was already in
pci_user.c. Use this infrastructure to add implement 32-bit support.

Obtained from: CheriBSD

[kib]

Why did you moved everything but pci bar mmap case ?

[brooks]

In D17324#369437, @kib wrote:

Why did you moved everything but pci bar mmap case ?

Because I already had this code (pre-dating the pci bar mmap case's existence). I'm happy to move it, but would prefer to do it in a separate change.

[kib]

In D17324#369486, @brooks wrote:

In D17324#369437, @kib wrote:

Why did you moved everything but pci bar mmap case ?

Because I already had this code (pre-dating the pci bar mmap case's existence). I'm happy to move it, but would prefer to do it in a separate change.

Ok. The move has more important consequence than just the code structure. Ioctl commands are specific to file descriptor, so the approach of freebsd32_ioctl() is flawed beyond repair. This is one of the reason of me asking about bar mmap.

[jhb]

Agree with kib on the general point that all of freebsd32_ioctl is probably busted and should be moved to the actual ioctl handlers.