board: openpiton: Remove <common.h> and add needed includes

Remove <common.h> from this board vendor directory and when needed
add missing include files directly.

Signed-off-by: Tom Rini <trini@konsulko.com>

board/openpiton/riscv64/openpiton-riscv64.c

@@ -8,7 +8,6 @@
  *   Pragnesh Patel <pragnesh.patel@sifive.com>
  *   Tianrui Wei <tianrui-wei@outlook.com>
  */
-#include <common.h>
 #include <init.h>
 #include <configs/openpiton-riscv64.h>
 #include <dm.h>