emu10k1.conf - Fix no sound problem when using SB Live! Platinum

Add asym to front, rear and center_lfe to prevent route change after
removed the lock.

After removed the lock, when application using "hw", "front", "rear",
"surround40" and "surround51",  the route of the front channel is
changed (lost right channel or both channels) when other application
using "front", "rear" or "center_lfe" to record

Signed-off-by: Raymond Yau <superquad.vortex2@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>