soc/intel/quark: Add PCIe reset support

Migrate PCIe reset from PlatformPciHelperLib in QuarkFspPkg into
coreboot.

Change-Id: I1c33fa16b0323091e8f9bd503bbfdb8a253a76d4
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/14944
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/mainboard/intel/galileo/gen2.h b/src/mainboard/intel/galileo/gen2.h
index 108971b..8eee744 100644
--- a/src/mainboard/intel/galileo/gen2.h
+++ b/src/mainboard/intel/galileo/gen2.h
@@ -13,6 +13,9 @@
  * GNU General Public License for more details.
  */
 
+/* PCIe reset pin */
+#define GEN2_PCI_RESET_RESUMEWELL_GPIO		0
+
 static const struct reg_script gen2_gpio_init[] = {
 	/* Initialize the legacy GPIO controller */
 	REG_LEG_GPIO_WRITE(R_QNC_GPIO_CGEN_CORE_WELL, 0x03),