SSYNC register was once defined as 0x34-37 in the old Intel datasheet,
but corrected later to 0x38-3b.  For fixing the register usage, a new
bit-flag is introduced for indicating the old ICH SSYNC register, and
ICH* PCI entries are added explicitly to enable this quirk.
Signed-off-by: Takashi Iwai <tiwai@suse.de>