Revert "arm64 Kconfig: Move LIST_POISON to a safe value"

This reverts commit 4003f6b.

This is a redefine of commit bf0c4e0 (arm64: kconfig: Move LIST_POISON
to a safe value)

Change-Id: Ibde683271af2bc982f3727a98ebd1530fc503dd1
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>

Author: Andy Yan

arch/arm64/Kconfig

@@ -158,10 +158,6 @@ config ARM64_CONT_SHIFT
 config NO_IOPORT_MAP
 	def_bool y if !PCI
 
-config ILLEGAL_POINTER_VALUE
-	hex
-	default 0xdead000000000000
-
 config STACKTRACE_SUPPORT
 	def_bool y