ALSA: seq: Fix comments of wrong client number for MIDI Passthrough

MIDI Passthrough sequencer client is assigned always to the fixed
number 14, while it's wrongly documented in the comments as if 62,
which was an old number that was used during development.  Fix all
those numbers.

Link: https://lore.kernel.org/r/20210727105232.7321-1-tiwai@suse.de


Signed-off-by: Takashi Iwai <tiwai@suse.de>