x86, kexec: x86_64: add kexec jump support for x86_64

Impact: New major feature

This patch add kexec jump support for x86_64. More information about
kexec jump can be found in corresponding x86_32 support patch.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 3175837..87717f3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1431,7 +1431,7 @@
 config KEXEC_JUMP
 	bool "kexec jump (EXPERIMENTAL)"
 	depends on EXPERIMENTAL
-	depends on KEXEC && HIBERNATION && X86_32
+	depends on KEXEC && HIBERNATION
 	---help---
 	  Jump between original kernel and kexeced kernel and invoke
 	  code in physical address mode via KEXEC