Kdump Update i386/x86_64

Hi,

Following set of patches is an update to kdump on i386 and x86_64. Changes
arises mainly due to review comments received during last posting of
kdump for x86_64.

Vivek Goyal:
	- i386 save ss esp bug fix
	- dynamic per cpu allocation of memory for saving cpu registers
	- export per cpu crash notes pointer through sysfs
	- save registers early (inline functions)

Murali M:
	- x86_64 add memmmap command line option
	- x86_64 add elfcorehdr command line option
	- x86_64 kexec on panic
	- x86_64 save cpu registers upon crash

Rachita Kothiyal:
	- read previous kernel's memory
	- kexec increase max segment limit

This set of patches has been tested on i386 and em64t x86_64 machine. Crash
dumps can be captured and opened using gdb and crash-4.0-2.12.

Corresponding kexec-tools patches are being posted in a separate set
on fastboot mailing list.

Thanks
Vivek