board: rpi: remove leftover CONFIG_HW_WATCHDOG block

This was added in commit 45a6d231b2 (bcm2835_wdt: support for the
BCM2835/2836 watchdog), which did do 'select HW_WATCHDOG'. That
incarnation of the watchdog driver later got removed in
c7adc0b5f9 (watchdog: bcm2835_wdt: Remove unused BCM283x watchdog
driver and its references), but this block was left behind.

Another rpi watchdog driver has since been added, but that does not
select HW_WATCHDOG, so this remains dead and unused. Remove it.

Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Reviewed-by: Peter Robinson <pbrobinson@gmail.com>

board/raspberrypi/rpi/rpi.c

@@ -494,10 +494,6 @@ static void get_board_revision(void)
 
 int board_init(void)
 {
-#ifdef CONFIG_HW_WATCHDOG
-	hw_watchdog_init();
-#endif
-
 	get_board_revision();
 
 	gd->bd->bi_boot_params = 0x100;