pci: allow disabling of pci init/enum via env

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 4b73a0f..6b36c18 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -458,6 +458,10 @@
 {
 	hose_head = NULL;
 
+	/* allow env to disable pci init/enum */
+	if (getenv("pcidisable") != NULL)
+		return;
+
 	/* now call board specific pci_init()... */
 	pci_init_board();
 }