HDA: Enable Mini-HDA and fix up PCH-HDA init

The SystemAgent contains a mini-hd audio controller at PCI 0:3.0
which uses the same verb table init sequence as the southbridge.

In order to avoid two copies of the verb table loading code I
separated out the HDA verb table functions into a file that can
be re-used and then added a minihd driver to the haswell northbridge.

The minihd verb table is the same across devices so it can live
within the minihd driver rather than needing to be specified in
each separate mainboard.

I also fixed up the driver for lynxpoint HDA by following the
reference code.

Without HDMI cable plugged in driver does not find any codec,
and it does not seem to re-probe when HDMI is connected.  We may
be missing kernel patches for this.

hda-intel 0000:00:03.0: no codecs found!

With a basic kernel patch to add 0x0a0c device ID to HDA driver
and with HDMI cable connected it is much happier:

snd_hda_intel 0000:00:03.0: irq 60 for MSI/MSI-X
input: HDA Intel MID HDMI/DP,pcm=3 as /devices/pci0000:00/0000:00:03.0/sound/card0/input9
snd_hda_intel 0000:00:1b.0: irq 61 for MSI/MSI-X
input: HDA Intel PCH Mic as /devices/pci0000:00/0000:00:1b.0/sound/card1/input10
input: HDA Intel PCH Headphone as /devices/pci0000:00/0000:00:1b.0/sound/card1/input11

Change-Id: Ifa587984be4fc2801704a0368b9cdf8379c2450e
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/59336
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/4318
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/northbridge/intel/haswell/early_init.c b/src/northbridge/intel/haswell/early_init.c
index 5b36418..7f9f187 100644
--- a/src/northbridge/intel/haswell/early_init.c
+++ b/src/northbridge/intel/haswell/early_init.c
@@ -103,8 +103,9 @@
 	/* Setup all BARs required for early PCIe and raminit */
 	haswell_setup_bars();
 
-	/* Device Enable */
-	pci_write_config32(PCI_DEV(0, 0, 0), DEVEN, DEVEN_HOST | DEVEN_IGD);
+	/* Device Enable: IGD and Mini-HD Audio */
+	pci_write_config32(PCI_DEV(0, 0, 0), DEVEN,
+			   DEVEN_D0EN | DEVEN_D2EN | DEVEN_D3EN);
 
 	haswell_setup_graphics();
 }