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>

include/init.h

@@ -310,6 +310,16 @@ int board_early_init_r(void);
  */
 int arch_initr_trap(void);
 
+/**
+ * init_addr_map()
+ *
+ * Initialize non-identity virtual-physical memory mappings for 32bit CPUs.
+ * It is called during the generic board init sequence, after relocation.
+ *
+ * Return: 0 if OK
+ */
+int init_addr_map(void);
+
 /**
  * main_loop() - Enter the main loop of U-Boot
  *