at91: Minor tweaks to SPL logic for space savings on smartweb

- spl_board_init is empty on smartweb so drop that function
- When CONFIG_AT91SAM9_WATCHDOG is set we do not disable the watchdog in
  SPL and instead let full U-Boot handle it.  Instead of an empty
  function just do not call a function.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-at91/spl_atmel.c b/arch/arm/mach-at91/spl_atmel.c
index 11db1e5..597ff8c 100644
--- a/arch/arm/mach-at91/spl_atmel.c
+++ b/arch/arm/mach-at91/spl_atmel.c
@@ -98,8 +98,10 @@
 	configure_2nd_sram_as_l2_cache();
 #endif
 
+#if !defined(CONFIG_AT91SAM9_WATCHDOG)
 	/* disable watchdog */
 	at91_disable_wdt();
+#endif
 
 	/* PMC configuration */
 	at91_pmc_init();