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

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

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

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

@@ -8,6 +8,7 @@
 #define __ASM_ARC_U_BOOT_H__
 
 #include <asm-generic/u-boot.h>
+#include <asm/u-boot-arc.h>
 
 /* For image.h:image_check_target_arch() */
 #define IH_ARCH_DEFAULT IH_ARCH_ARC

include/common.h

@@ -445,7 +445,7 @@ static inline int setenv_addr(const char *varname, const void *addr)
 # include <asm/u-boot-mips.h>
 #endif /* CONFIG_MIPS */
 #ifdef CONFIG_ARC
-# include <asm/u-boot-arc.h>
+# include <asm/u-boot.h>
 #endif /* CONFIG_ARC */
 
 #ifdef CONFIG_AUTO_COMPLETE