The functions dynamically loaded via plugin aren't fully listed
in the exported functions in Versions file. This caused errors at
opening devices with such plugins.
The entries in the current Versions file don't work as expected.
Since the first ALSA_0.9 has already snd_* global definitions, all
the rest are simply ignored. Some symbols (e.g. snd_hw_params_*)
indeed work because they have explicit symver definitions, but
ALSA_0.9.6 and later are all superfluous.
This patch clean up these useless entries. Also, the patch restricts
the matching patterns for _snd_* and __snd_* entries to reduce the
unneeded export symbols.
Export helper functions to convert dB level and range.
snd_tlv_*dB*() are to convert dB level or range directly from TLV data.
snd_ctl_*dB*() are to get dB level or range from a control element.
