nds32: Make u-boot-nds32.h a private header

Rather than including this arch-specific header file in common.h, include
it from within nds32's u-boot.h header.

Signed-off-by: Simon Glass <sjg@chromium.org>

arch/nds32/include/asm/u-boot.h

@@ -20,6 +20,8 @@
 #ifndef _U_BOOT_H_
 #define _U_BOOT_H_	1
 
+#include <asm/u-boot-nds32.h>
+
 #include <environment.h>
 
 typedef struct bd_info {

include/common.h

@@ -439,7 +439,7 @@ static inline int setenv_addr(const char *varname, const void *addr)
 #ifdef CONFIG_NDS32
 # include <asm/mach-types.h>
 # include <asm/setup.h>
-# include <asm/u-boot-nds32.h>
+# include <asm/u-boot.h>
 #endif /* CONFIG_NDS32 */
 #ifdef CONFIG_MIPS
 # include <asm/u-boot.h>