[IA64] ia64 kexec/kdump backport

[IA64] ia64 kexec/kdump backport

From: Simon Horman <horms@verge.net.au>

* From Linux Upstream, commit a79561134f38de12dce14ed72138f38e55ef53fc
* Trivial backport to linux-2.6.18-xen of the following hunks
  * arch/ia64/kernel/mca.c: hunk 2
  * include/asm-ia64/machvec.h: hunks 1 & 2
  * include/asm-ia64/machvec_sn2.h: hunk 1
  * meminit.h

[IA64] IA64 Kexec/kdump

Changes and updates.

1. Remove fake rendz path and related code according to discuss with Khalid Aziz.
2. fc.i offset fix in relocate_kernel.S.
3. iospic shutdown code eoi and mask race fix from Fujitsu.
4. Warm boot hook in machine_kexec to SN SAL code from Jack Steiner.
5. Send slave to SAL slave loop patch from Jay Lan.
6. Kdump on non-recoverable MCA event patch from Jay Lan
7. Use CTL_UNNUMBERED in kdump_on_init sysctl.

Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>