sh: remove board_time_init() callback

The only remaining user of board_time_init() is the of-generic
machine, and that just calls the global timer_init() function.
Calling that one has no effect on non-DT platforms, so we can
simply call it unconditionally in place of board_time_init().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Documentation/sh/new-machine.txt

@@ -116,7 +116,6 @@ might look something like:
  * arch/sh/boards/vapor/setup.c - Setup code for imaginary board
  */
 #include <linux/init.h>
-#include <asm/rtc.h> /* for board_time_init() */
 
 const char *get_system_type(void)
 {
@@ -132,13 +131,6 @@ int __init platform_setup(void)
 	 * this board.
 	 */
 
-  	/* 
-	 * Presume all FooTech boards have the same broken timer,
-	 * and also presume that we've defined foo_timer_init to
-	 * do something useful.
-	 */
-  	board_time_init = foo_timer_init;
-
 	/* Start-up imaginary PCI ... */
 
 	/* And whatever else ... */