xtensa: Remove <common.h> and add needed includes

Remove <common.h> from all xtensa architecture files and when needed add
missing include files directly.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/xtensa/cpu/cpu.c b/arch/xtensa/cpu/cpu.c
index 98d9753..abcd8f7 100644
--- a/arch/xtensa/cpu/cpu.c
+++ b/arch/xtensa/cpu/cpu.c
@@ -8,7 +8,7 @@
  * CPU specific code
  */
 
-#include <common.h>
+#include <config.h>
 #include <command.h>
 #include <init.h>
 #include <vsprintf.h>