memory_bus: Move related declarations into new `chipdrivers/memory_bus.h`

Change-Id: I2bef65de77860d049ec3d9938ae777c5f929c258
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.sourcearcade.org/c/flashprog/+/438
diff --git a/flashchips.c b/flashchips.c
index 2b431eb..dd48f69 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -24,6 +24,7 @@
 #include "chipdrivers.h"
 #include "chipdrivers/edi.h"
 #include "chipdrivers/spi.h"
+#include "chipdrivers/memory_bus.h"
 #include "writeprotect.h"
 
 /**