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/memory_bus.c b/memory_bus.c
index 3ca71d1..61058b9 100644
--- a/memory_bus.c
+++ b/memory_bus.c
@@ -20,7 +20,7 @@
 #include "flash.h"
 #include "programmer.h"
 
-#include "chipdrivers.h"
+#include "chipdrivers/memory_bus.h"
 
 static void *programmer_map_flash_region(const struct flashctx *flash, const char *descr,
 					 uintptr_t phys_addr, size_t len)