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/sbc8548/sbc8548.c b/board/sbc8548/sbc8548.c
index 0c36ded..d246dce 100644
--- a/board/sbc8548/sbc8548.c
+++ b/board/sbc8548/sbc8548.c
@@ -10,6 +10,7 @@
  */
 
 #include <common.h>
+#include <init.h>
 #include <pci.h>
 #include <asm/processor.h>
 #include <asm/immap_85xx.h>