ALSA: hda - Keep halting ALC5505 DSP

ALC5505 DSP is enabled even though we don't use the features yet at
all.  This results in the unnecessarily high power consumption, more
than 100mV higher.  Until we implement the DSP support, better to
bypass DSP for saving more power.

Reported-by: Mengdong Lin <mengdong.lin@intel.com>
[Patch modified by Mengdong to cal alc5505_dsp_init() with extra
acl5505_dsp_halt().]

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