Disable probing for one variant of MCP55 to enable Tyan S2915

Fix Tyan S2915 OEM board by commenting out MCP55 LPC bridge PCI ID
10de:0361 which is the secondary LPC bridge.

The same effect could be achieved by refusing to run enable_flash_mcp55
if the device class is not ISA bridge [0601].

Thanks to Alessandro Polverini, Joel Robertson, Nicolas Aveline, Phil
LoCascio and Nils-Helge Garli Hegvik for testing flashrom on hardware
and Michael Karcher for analyzing the factory BIOS for clues. In the
end, no board enable was needed and it was a pure chipset issue.

Corresponding to flashrom svn r1007.
Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Michael Karcher <flashrom@mkarcher.dialup.fu-berlin.de>

chipset_enable.c

@@ -1354,7 +1354,15 @@ const struct penable chipset_enables[] = {
 	{0x10de, 0x0262, NT, "NVIDIA", "MCP51",		enable_flash_ck804},
 	{0x10de, 0x0263, NT, "NVIDIA", "MCP51",		enable_flash_ck804},
 	{0x10de, 0x0360, OK, "NVIDIA", "MCP55",		enable_flash_mcp55}, /* M57SLI*/
-	{0x10de, 0x0361, OK, "NVIDIA", "MCP55",		enable_flash_mcp55}, /* LPC */
+	/* 10de:0361 is present in Tyan S2915 OEM systems, but not connected to
+	 * the flash chip. Instead, 10de:0364 is connected to the flash chip.
+	 * Until we have PCI device class matching or some fallback mechanism,
+	 * this is needed to get flashrom working on Tyan S2915 and maybe other
+	 * dual-MCP55 boards.
+	 */
+#if 0
+	{0x10de, 0x0361, NT, "NVIDIA", "MCP55",		enable_flash_mcp55}, /* LPC */
+#endif
 	{0x10de, 0x0362, OK, "NVIDIA", "MCP55",		enable_flash_mcp55}, /* LPC */
 	{0x10de, 0x0363, OK, "NVIDIA", "MCP55",		enable_flash_mcp55}, /* LPC */
 	{0x10de, 0x0364, OK, "NVIDIA", "MCP55",		enable_flash_mcp55}, /* LPC */