init_task: Replace CONFIG_HAVE_GENERIC_INIT_TASK

Now that all archs except ia64 are converted, replace the config and
let the ia64 select CONFIG_ARCH_INIT_TASK

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20120503085035.867948914@linutronix.de

arch/tile/Kconfig

@@ -13,7 +13,6 @@ config TILE
 	select GENERIC_IRQ_SHOW
 	select SYS_HYPERVISOR
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
-	select HAVE_GENERIC_INIT_TASK
 
 # FIXME: investigate whether we need/want these options.
 #	select HAVE_IOREMAP_PROT