common: board_r: move init_addr_map() to init.h

asm/mmu.h include is currently guarded by CONFIG_ADDR_MAP ifdef because
the header is only present on arm and powerpc. In order to remove the
dependency on this header and the associated ifdef, move init_addr_map()
declaration to init.h, since it is only called during the common init
sequence.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>

arch/powerpc/include/asm/mmu.h

@@ -137,10 +137,6 @@ typedef struct _MMU_context {
 extern void _tlbie(unsigned long va);	/* invalidate a TLB entry */
 extern void _tlbia(void);		/* invalidate all TLB entries */
 
-#ifdef CONFIG_ADDR_MAP
-extern int init_addr_map(void);
-#endif
-
 typedef enum {
 	IBAT0 = 0, IBAT1, IBAT2, IBAT3,
 	DBAT0, DBAT1, DBAT2, DBAT3,