ALSA: hda - Fix stac92hd83xxx_amp_nids[]

Fix the bug introduced in commit c15c5060fc32d7de7cde76aa61e98bae1334d82e:
  sound/pci/hda/patch_sigmatel.c: In function ‘patch_stac92hd83xxx’:
  sound/pci/hda/patch_sigmatel.c:4765: warning: assignment from incompatible pointer type

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

sound/pci/hda/patch_sigmatel.c

@@ -336,7 +336,7 @@ static unsigned int stac92hd83xxx_pwr_mapping[4] = {
 	0x03, 0x0c, 0x10, 0x40,
 };
 
-static unsigned int stac92hd83xxx_amp_nids[1] = {
+static hda_nid_t stac92hd83xxx_amp_nids[1] = {
 	0xc,
 };