ALSA: emu10k1 - Remove "Front" controls only for STAC9758/59

ALSA: emu10k1 - Remove "Front" controls only for STAC9758/59

Remove "Front Playback Volume" and "Front Playback Switch" from emu10k1 only
for STAC9758/59

Since commit 8a4dad58b91d99ba46211606f9d09e6933ed09f6
      "Fix the confliction of 'Front' control",
the "Front Playback Volume" control created by commit
	d4fca054509662286b383490d7c6e911631edb68
	"emu10k1: Front channels via fxbus 8 and 9"
was removed

"Front Playback Volume" and "Surround Playback Volume" have same dB range
since I2S DAC of SB Live! and SB Live! Platinum does not has any hardware
volume control.

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