Fix external WC/AES clock selection

Seems my OSX driver source doesn't comply with the actual hardware. ;)
Fix ioctl example program to reflect new clock source order
[README]: Mark external clock selection as working
Use snd_ctl_enum_info() to shorten the driver

We did the same in hdspm.c.
[README] Mark MIDI I/O as working

Tested by Marcin Pączkowski
Refresh below38.patch
Refresh oldkernel.patch
[README] Acknowledge Marcin's contribution