include: Revert a couple of include changes that are no longer needed since the last upstream merge.

panda/src/framework/rock_floor.rgb_src.c

@@ -1,4 +1,3 @@
-#include "stddef.h" // size_t
 
 /*
  * This table was generated by the command:

panda/src/framework/shuttle_controls.bam_src.c

@@ -1,4 +1,4 @@
-#include "stddef.h" // size_t
+
 /*
  * This table was generated by the command:
  *