bebob: Fix failure to detect source of clock for Terratec Phase 88

Terratec Phase 88 has two Selector Function Blocks of AVC Audio subunit
to switch source of clock. One is to switch internal/external for source
and another is to switch word/spdif for external clock.

The IDs for these Selector Function Blocks are 9 and 8. But in current
implementation they're 0 and 0. This bug causes failure to open PCM
device with -ENOSYS.