A cosmetic but useful change on soundcard.h

[DervishD]

    Hello all :)

    I've seen that the device names and device labels for the mixer
on soundcard.h are somewhat incongruent. It seems that the first
labels and names length is 5 characters, even padding shorter ones
with spaces, but newly added labels are longer than that.

    Would be possible (I can make the patch, is *very* easy) to pad
*all* labels and names so all them are of the same size? Moreover,
adding a #define with that size would help a lot user-space apps like
mixers and the like. Simply using '80' as the size doesn't help, and
I've seen a couple of mixer doing this...

    How about it?

    Raśl