common: Move pci_init_board() out of common.h

This function can be dropped when all boards use driver model for PCI. For
now, move it into init.h with a comment.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/board/keymile/kmp204x/pci.c b/board/keymile/kmp204x/pci.c
index 965a8ce..a804745 100644
--- a/board/keymile/kmp204x/pci.c
+++ b/board/keymile/kmp204x/pci.c
@@ -8,6 +8,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <init.h>
 #include <pci.h>
 #include <asm/fsl_pci.h>
 #include <linux/libfdt.h>